common/hush.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * sh.c -- a prototype Bourne shell grammar parser
   4  *      Intended to follow the original Thompson and Ritchie
   5  *      "small and simple is beautiful" philosophy, which
   6  *      incidentally is a good match to today's BusyBox.
   7  *
   8  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   9  *
  10  * Credits:
  11  *      The parser routines proper are all original material, first
  12  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  13  *      The execution engine, the builtins, and much of the underlying
  14  *      support has been adapted from busybox-0.49pre's lash,
  15  *      which is Copyright (C) 2000 by Lineo, Inc., and
  16  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  17  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  18  *      Erik W. Troan, which they placed in the public domain.  I don't know
  19  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  20  * Other credits:
  21  *      simple_itoa() was lifted from boa-0.93.15
  22  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  23  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  24  *        and many builtins derived from contributions by Erik Andersen
  25  *      miscellaneous bugfixes from Matt Kraai
  26  *
  27  * There are two big (and related) architecture differences between
  28  * this parser and the lash parser.  One is that this version is
  29  * actually designed from the ground up to understand nearly all
  30  * of the Bourne grammar.  The second, consequential change is that
  31  * the parser and input reader have been turned inside out.  Now,
  32  * the parser is in control, and asks for input as needed.  The old
  33  * way had the input reader in control, and it asked for parsing to
  34  * take place as needed.  The new way makes it much easier to properly
  35  * handle the recursion implicit in the various substitutions, especially
  36  * across continuation lines.
  37  *
  38  * Bash grammar not implemented: (how many of these were in original sh?)
  39  *      $@ (those sure look like weird quoting rules)
  40  *      $_
  41  *      ! negation operator for pipes
  42  *      &> and >& redirection of stdout+stderr
  43  *      Brace Expansion
  44  *      Tilde Expansion
  45  *      fancy forms of Parameter Expansion
  46  *      aliases
  47  *      Arithmetic Expansion
  48  *      <(list) and >(list) Process Substitution
  49  *      reserved words: case, esac, select, function
  50  *      Here Documents ( << word )
  51  *      Functions
  52  * Major bugs:
  53  *      job handling woefully incomplete and buggy
  54  *      reserved word execution woefully incomplete and buggy
  55  * to-do:
  56  *      port selected bugfixes from post-0.49 busybox lash - done?
  57  *      finish implementing reserved words: for, while, until, do, done
  58  *      change { and } from special chars to reserved words
  59  *      builtins: break, continue, eval, return, set, trap, ulimit
  60  *      test magic exec
  61  *      handle children going into background
  62  *      clean up recognition of null pipes
  63  *      check setting of global_argc and global_argv
  64  *      control-C handling, probably with longjmp
  65  *      follow IFS rules more precisely, including update semantics
  66  *      figure out what to do with backslash-newline
  67  *      explain why we use signal instead of sigaction
  68  *      propagate syntax errors, die on resource errors?
  69  *      continuation lines, both explicit and implicit - done?
  70  *      memory leak finding and plugging - done?
  71  *      more testing, especially quoting rules and redirection
  72  *      document how quoting rules not precisely followed for variable assignments
  73  *      maybe change map[] to use 2-bit entries
  74  *      (eventually) remove all the printf's
  75  *
  76  * This program is free software; you can redistribute it and/or modify
  77  * it under the terms of the GNU General Public License as published by
  78  * the Free Software Foundation; either version 2 of the License, or
  79  * (at your option) any later version.
  80  *
  81  * This program is distributed in the hope that it will be useful,
  82  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  83  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  84  * General Public License for more details.
  85  *
  86  * You should have received a copy of the GNU General Public License
  87  * along with this program; if not, write to the Free Software
  88  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  89  */
  90 #define __U_BOOT__
  91 #ifdef __U_BOOT__
  92 #include <malloc.h>         /* malloc, free, realloc*/
  93 #include <linux/ctype.h>    /* isalpha, isdigit */
  94 #include <common.h>        /* readline */
  95 #include <hush.h>
  96 #include <command.h>        /* find_cmd */
  97 #include <cmd_bootm.h>      /* do_bootd */
  98 #endif
  99 #ifdef CFG_HUSH_PARSER
 100 #ifndef __U_BOOT__
 101 #include <ctype.h>     /* isalpha, isdigit */
 102 #include <unistd.h>    /* getpid */
 103 #include <stdlib.h>    /* getenv, atoi */
 104 #include <string.h>    /* strchr */
 105 #include <stdio.h>     /* popen etc. */
 106 #include <glob.h>      /* glob, of course */
 107 #include <stdarg.h>    /* va_list */
 108 #include <errno.h>
 109 #include <fcntl.h>
 110 #include <getopt.h>    /* should be pretty obvious */
 111
 112 #include <sys/stat.h>  /* ulimit */
 113 #include <sys/types.h>
 114 #include <sys/wait.h>
 115 #include <signal.h>
 116
 117 /* #include <dmalloc.h> */
 118 /* #define DEBUG_SHELL */
 119
 120 #ifdef BB_VER
 121 #include "busybox.h"
 122 #include "cmdedit.h"
 123 #else
 124 #define applet_name "hush"
 125 #include "standalone.h"
 126 #define hush_main main
 127 #undef BB_FEATURE_SH_FANCY_PROMPT
 128 #endif
 129 #endif
 130 #define SPECIAL_VAR_SYMBOL 03
 131 #ifndef __U_BOOT__
 132 #define FLAG_EXIT_FROM_LOOP 1
 133 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 134 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 135
 136 #endif
 137
 138 #ifdef __U_BOOT__
 139 #define EXIT_SUCCESS 0
 140 #define EOF -1
 141 #define syntax() syntax_err()
 142 #define xstrdup strdup
 143 #define error_msg printf
 144 #else
 145 typedef enum {
 146         REDIRECT_INPUT     = 1,
 147         REDIRECT_OVERWRITE = 2,
 148         REDIRECT_APPEND    = 3,
 149         REDIRECT_HEREIS    = 4,
 150         REDIRECT_IO        = 5
 151 } redir_type;
 152
 153 /* The descrip member of this structure is only used to make debugging
 154  * output pretty */
 155 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 156         { 0,                         0, "()" },
 157         { O_RDONLY,                  0, "<"  },
 158         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 159         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 160         { O_RDONLY,                 -1, "<<" },
 161         { O_RDWR,                    1, "<>" }
 162 };
 163 #endif
 164
 165 typedef enum {
 166         PIPE_SEQ = 1,
 167         PIPE_AND = 2,
 168         PIPE_OR  = 3,
 169         PIPE_BG  = 4,
 170 } pipe_style;
 171
 172 /* might eventually control execution */
 173 typedef enum {
 174         RES_NONE  = 0,
 175         RES_IF    = 1,
 176         RES_THEN  = 2,
 177         RES_ELIF  = 3,
 178         RES_ELSE  = 4,
 179         RES_FI    = 5,
 180         RES_FOR   = 6,
 181         RES_WHILE = 7,
 182         RES_UNTIL = 8,
 183         RES_DO    = 9,
 184         RES_DONE  = 10,
 185         RES_XXXX  = 11,
 186         RES_IN    = 12,
 187         RES_SNTX  = 13
 188 } reserved_style;
 189 #define FLAG_END   (1<<RES_NONE)
 190 #define FLAG_IF    (1<<RES_IF)
 191 #define FLAG_THEN  (1<<RES_THEN)
 192 #define FLAG_ELIF  (1<<RES_ELIF)
 193 #define FLAG_ELSE  (1<<RES_ELSE)
 194 #define FLAG_FI    (1<<RES_FI)
 195 #define FLAG_FOR   (1<<RES_FOR)
 196 #define FLAG_WHILE (1<<RES_WHILE)
 197 #define FLAG_UNTIL (1<<RES_UNTIL)
 198 #define FLAG_DO    (1<<RES_DO)
 199 #define FLAG_DONE  (1<<RES_DONE)
 200 #define FLAG_IN    (1<<RES_IN)
 201 #define FLAG_START (1<<RES_XXXX)
 202
 203 /* This holds pointers to the various results of parsing */
 204 struct p_context {
 205         struct child_prog *child;
 206         struct pipe *list_head;
 207         struct pipe *pipe;
 208 #ifndef __U_BOOT__
 209         struct redir_struct *pending_redirect;
 210 #endif
 211         reserved_style w;
 212         int old_flag;                           /* for figuring out valid reserved words */
 213         struct p_context *stack;
 214         int type;                       /* define type of parser : ";$" common or special symbol */
 215         /* How about quoting status? */
 216 };
 217
 218 #ifndef __U_BOOT__
 219 struct redir_struct {
 220         redir_type type;                        /* type of redirection */
 221         int fd;                                         /* file descriptor being redirected */
 222         int dup;                                        /* -1, or file descriptor being duplicated */
 223         struct redir_struct *next;      /* pointer to the next redirect in the list */
 224         glob_t word;                            /* *word.gl_pathv is the filename */
 225 };
 226 #endif
 227
 228 struct child_prog {
 229 #ifndef __U_BOOT__
 230         pid_t pid;                                      /* 0 if exited */
 231 #endif
 232         char **argv;                            /* program name and arguments */
 233 #ifdef __U_BOOT__
 234         int    argc;                            /* number of program arguments */
 235 #endif
 236         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 237 #ifndef __U_BOOT__
 238         int subshell;                           /* flag, non-zero if group must be forked */
 239         struct redir_struct *redirects; /* I/O redirections */
 240         glob_t glob_result;                     /* result of parameter globbing */
 241         int is_stopped;                         /* is the program currently running? */
 242         struct pipe *family;            /* pointer back to the child's parent pipe */
 243 #endif
 244         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 245         int type;
 246 };
 247
 248 struct pipe {
 249 #ifndef __U_BOOT__
 250         int jobid;                                      /* job number */
 251 #endif
 252         int num_progs;                          /* total number of programs in job */
 253 #ifndef __U_BOOT__
 254         int running_progs;                      /* number of programs running */
 255         char *text;                                     /* name of job */
 256         char *cmdbuf;                           /* buffer various argv's point into */
 257         pid_t pgrp;                                     /* process group ID for the job */
 258 #endif
 259         struct child_prog *progs;       /* array of commands in pipe */
 260         struct pipe *next;                      /* to track background commands */
 261 #ifndef __U_BOOT__
 262         int stopped_progs;                      /* number of programs alive, but stopped */
 263         int job_context;                        /* bitmask defining current context */
 264 #endif
 265         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 266         reserved_style r_mode;          /* supports if, for, while, until */
 267 };
 268
 269 #ifndef __U_BOOT__
 270 struct close_me {
 271         int fd;
 272         struct close_me *next;
 273 };
 274 #endif
 275
 276 struct variables {
 277         char *name;
 278         char *value;
 279         int flg_export;
 280         int flg_read_only;
 281         struct variables *next;
 282 };
 283
 284 /* globals, connect us to the outside world
 285  * the first three support $?, $#, and $1 */
 286 #ifndef __U_BOOT__
 287 char **global_argv;
 288 unsigned int global_argc;
 289 #endif
 290 unsigned int last_return_code;
 291 #ifndef __U_BOOT__
 292 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 293 #endif
 294
 295 /* "globals" within this file */
 296 static char *ifs;
 297 static char map[256];
 298 #ifndef __U_BOOT__
 299 static int fake_mode;
 300 static int interactive;
 301 static struct close_me *close_me_head;
 302 static const char *cwd;
 303 static struct pipe *job_list;
 304 static unsigned int last_bg_pid;
 305 static unsigned int last_jobid;
 306 static unsigned int shell_terminal;
 307 static char *PS1;
 308 static char *PS2;
 309 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 310 struct variables *top_vars = &shell_ver;
 311 #else
 312 static int flag_repeat = 0;
 313 static int do_repeat = 0;
 314 static struct variables *top_vars ;
 315 #endif /*__U_BOOT__ */
 316
 317 #define B_CHUNK (100)
 318 #define B_NOSPAC 1
 319
 320 typedef struct {
 321         char *data;
 322         int length;
 323         int maxlen;
 324         int quote;
 325         int nonnull;
 326 } o_string;
 327 #define NULL_O_STRING {NULL,0,0,0,0}
 328 /* used for initialization:
 329         o_string foo = NULL_O_STRING; */
 330
 331 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 332  * available?  Where is it documented? */
 333 struct in_str {
 334         const char *p;
 335 #ifndef __U_BOOT__
 336         char peek_buf[2];
 337 #endif
 338         int __promptme;
 339         int promptmode;
 340 #ifndef __U_BOOT__
 341         FILE *file;
 342 #endif
 343         int (*get) (struct in_str *);
 344         int (*peek) (struct in_str *);
 345 };
 346 #define b_getch(input) ((input)->get(input))
 347 #define b_peek(input) ((input)->peek(input))
 348
 349 #ifndef __U_BOOT__
 350 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 351
 352 struct built_in_command {
 353         char *cmd;                                      /* name */
 354         char *descr;                            /* description */
 355         int (*function) (struct child_prog *);  /* function ptr */
 356 };
 357 #endif
 358
 359 /* belongs in busybox.h */
 360 static inline int max(int a, int b) {
 361         return (a>b)?a:b;
 362 }
 363
 364 /* This should be in utility.c */
 365 #ifdef DEBUG_SHELL
 366 #ifndef __U_BOOT__
 367 static void debug_printf(const char *format, ...)
 368 {
 369         va_list args;
 370         va_start(args, format);
 371         vfprintf(stderr, format, args);
 372         va_end(args);
 373 }
 374 #else
 375 #define debug_printf printf             /* U-Boot debug flag */
 376 #endif
 377 #else
 378 static inline void debug_printf(const char *format, ...) { }
 379 #endif
 380 #define final_printf debug_printf
 381
 382 #ifdef __U_BOOT__
 383 static void syntax_err(void) {
 384          printf("syntax error\n");
 385 }
 386 #else
 387 static void __syntax(char *file, int line) {
 388         error_msg("syntax error %s:%d", file, line);
 389 }
 390 #define syntax() __syntax(__FILE__, __LINE__)
 391 #endif
 392
 393 #ifdef __U_BOOT__
 394 static void *xmalloc(size_t size);
 395 static void *xrealloc(void *ptr, size_t size);
 396 #else
 397 /* Index of subroutines: */
 398 /*   function prototypes for builtins */
 399 static int builtin_cd(struct child_prog *child);
 400 static int builtin_env(struct child_prog *child);
 401 static int builtin_eval(struct child_prog *child);
 402 static int builtin_exec(struct child_prog *child);
 403 static int builtin_exit(struct child_prog *child);
 404 static int builtin_export(struct child_prog *child);
 405 static int builtin_fg_bg(struct child_prog *child);
 406 static int builtin_help(struct child_prog *child);
 407 static int builtin_jobs(struct child_prog *child);
 408 static int builtin_pwd(struct child_prog *child);
 409 static int builtin_read(struct child_prog *child);
 410 static int builtin_set(struct child_prog *child);
 411 static int builtin_shift(struct child_prog *child);
 412 static int builtin_source(struct child_prog *child);
 413 static int builtin_umask(struct child_prog *child);
 414 static int builtin_unset(struct child_prog *child);
 415 static int builtin_not_written(struct child_prog *child);
 416 #endif
 417 /*   o_string manipulation: */
 418 static int b_check_space(o_string *o, int len);
 419 static int b_addchr(o_string *o, int ch);
 420 static void b_reset(o_string *o);
 421 static int b_addqchr(o_string *o, int ch, int quote);
 422 static int b_adduint(o_string *o, unsigned int i);
 423 /*  in_str manipulations: */
 424 static int static_get(struct in_str *i);
 425 static int static_peek(struct in_str *i);
 426 static int file_get(struct in_str *i);
 427 static int file_peek(struct in_str *i);
 428 #ifndef __U_BOOT__
 429 static void setup_file_in_str(struct in_str *i, FILE *f);
 430 #else
 431 static void setup_file_in_str(struct in_str *i);
 432 #endif
 433 static void setup_string_in_str(struct in_str *i, const char *s);
 434 #ifndef __U_BOOT__
 435 /*  close_me manipulations: */
 436 static void mark_open(int fd);
 437 static void mark_closed(int fd);
 438 static void close_all();
 439 #endif
 440 /*  "run" the final data structures: */
 441 static char *indenter(int i);
 442 static int free_pipe_list(struct pipe *head, int indent);
 443 static int free_pipe(struct pipe *pi, int indent);
 444 /*  really run the final data structures: */
 445 #ifndef __U_BOOT__
 446 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 447 #endif
 448 static int run_list_real(struct pipe *pi);
 449 #ifndef __U_BOOT__
 450 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 451 #endif
 452 static int run_pipe_real(struct pipe *pi);
 453 /*   extended glob support: */
 454 #ifndef __U_BOOT__
 455 static int globhack(const char *src, int flags, glob_t *pglob);
 456 static int glob_needed(const char *s);
 457 static int xglob(o_string *dest, int flags, glob_t *pglob);
 458 #endif
 459 /*   variable assignment: */
 460 static int is_assignment(const char *s);
 461 /*   data structure manipulation: */
 462 #ifndef __U_BOOT__
 463 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 464 #endif
 465 static void initialize_context(struct p_context *ctx);
 466 static int done_word(o_string *dest, struct p_context *ctx);
 467 static int done_command(struct p_context *ctx);
 468 static int done_pipe(struct p_context *ctx, pipe_style type);
 469 /*   primary string parsing: */
 470 #ifndef __U_BOOT__
 471 static int redirect_dup_num(struct in_str *input);
 472 static int redirect_opt_num(o_string *o);
 473 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 474 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 475 #endif
 476 static char *lookup_param(char *src);
 477 static char *make_string(char **inp);
 478 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 479 #ifndef __U_BOOT__
 480 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 481 #endif
 482 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 483 /*   setup: */
 484 static int parse_stream_outer(struct in_str *inp, int flag);
 485 #ifndef __U_BOOT__
 486 static int parse_string_outer(const char *s, int flag);
 487 static int parse_file_outer(FILE *f);
 488 #endif
 489 #ifndef __U_BOOT__
 490 /*   job management: */
 491 static int checkjobs(struct pipe* fg_pipe);
 492 static void insert_bg_job(struct pipe *pi);
 493 static void remove_bg_job(struct pipe *pi);
 494 #endif
 495 /*     local variable support */
 496 static char **make_list_in(char **inp, char *name);
 497 static char *insert_var_value(char *inp);
 498 static char *get_local_var(const char *var);
 499 #ifndef __U_BOOT__
 500 static void  unset_local_var(const char *name);
 501 #endif
 502 static int set_local_var(const char *s, int flg_export);
 503
 504 #ifndef __U_BOOT__
 505 /* Table of built-in functions.  They can be forked or not, depending on
 506  * context: within pipes, they fork.  As simple commands, they do not.
 507  * When used in non-forking context, they can change global variables
 508  * in the parent shell process.  If forked, of course they can not.
 509  * For example, 'unset foo | whatever' will parse and run, but foo will
 510  * still be set at the end. */
 511 static struct built_in_command bltins[] = {
 512         {"bg", "Resume a job in the background", builtin_fg_bg},
 513         {"break", "Exit for, while or until loop", builtin_not_written},
 514         {"cd", "Change working directory", builtin_cd},
 515         {"continue", "Continue for, while or until loop", builtin_not_written},
 516         {"env", "Print all environment variables", builtin_env},
 517         {"eval", "Construct and run shell command", builtin_eval},
 518         {"exec", "Exec command, replacing this shell with the exec'd process",
 519                 builtin_exec},
 520         {"exit", "Exit from shell()", builtin_exit},
 521         {"export", "Set environment variable", builtin_export},
 522         {"fg", "Bring job into the foreground", builtin_fg_bg},
 523         {"jobs", "Lists the active jobs", builtin_jobs},
 524         {"pwd", "Print current directory", builtin_pwd},
 525         {"read", "Input environment variable", builtin_read},
 526         {"return", "Return from a function", builtin_not_written},
 527         {"set", "Set/unset shell local variables", builtin_set},
 528         {"shift", "Shift positional parameters", builtin_shift},
 529         {"trap", "Trap signals", builtin_not_written},
 530         {"ulimit","Controls resource limits", builtin_not_written},
 531         {"umask","Sets file creation mask", builtin_umask},
 532         {"unset", "Unset environment variable", builtin_unset},
 533         {".", "Source-in and run commands in a file", builtin_source},
 534         {"help", "List shell built-in commands", builtin_help},
 535         {NULL, NULL, NULL}
 536 };
 537
 538 static const char *set_cwd(void)
 539 {
 540         if(cwd==unknown)
 541                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 542         cwd = xgetcwd((char *)cwd);
 543         if (!cwd)
 544                 cwd = unknown;
 545         return cwd;
 546 }
 547
 548 /* built-in 'eval' handler */
 549 static int builtin_eval(struct child_prog *child)
 550 {
 551         char *str = NULL;
 552         int rcode = EXIT_SUCCESS;
 553
 554         if (child->argv[1]) {
 555                 str = make_string(child->argv + 1);
 556                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 557                                         FLAG_PARSE_SEMICOLON);
 558                 free(str);
 559                 rcode = last_return_code;
 560         }
 561         return rcode;
 562 }
 563
 564 /* built-in 'cd <path>' handler */
 565 static int builtin_cd(struct child_prog *child)
 566 {
 567         char *newdir;
 568         if (child->argv[1] == NULL)
 569                 newdir = getenv("HOME");
 570         else
 571                 newdir = child->argv[1];
 572         if (chdir(newdir)) {
 573                 printf("cd: %s: %s\n", newdir, strerror(errno));
 574                 return EXIT_FAILURE;
 575         }
 576         set_cwd();
 577         return EXIT_SUCCESS;
 578 }
 579
 580 /* built-in 'env' handler */
 581 static int builtin_env(struct child_prog *dummy)
 582 {
 583         char **e = environ;
 584         if (e == NULL) return EXIT_FAILURE;
 585         for (; *e; e++) {
 586                 puts(*e);
 587         }
 588         return EXIT_SUCCESS;
 589 }
 590
 591 /* built-in 'exec' handler */
 592 static int builtin_exec(struct child_prog *child)
 593 {
 594         if (child->argv[1] == NULL)
 595                 return EXIT_SUCCESS;   /* Really? */
 596         child->argv++;
 597         pseudo_exec(child);
 598         /* never returns */
 599 }
 600
 601 /* built-in 'exit' handler */
 602 static int builtin_exit(struct child_prog *child)
 603 {
 604         if (child->argv[1] == NULL)
 605                 exit(last_return_code);
 606         exit (atoi(child->argv[1]));
 607 }
 608
 609 /* built-in 'export VAR=value' handler */
 610 static int builtin_export(struct child_prog *child)
 611 {
 612         int res = 0;
 613         char *name = child->argv[1];
 614
 615         if (name == NULL) {
 616                 return (builtin_env(child));
 617         }
 618
 619         name = strdup(name);
 620
 621         if(name) {
 622                 char *value = strchr(name, '=');
 623
 624                 if (!value) {
 625                         char *tmp;
 626                         /* They are exporting something without an =VALUE */
 627
 628                         value = get_local_var(name);
 629                         if (value) {
 630                                 size_t ln = strlen(name);
 631
 632                                 tmp = realloc(name, ln+strlen(value)+2);
 633                                 if(tmp==NULL)
 634                                         res = -1;
 635                                 else {
 636                                         sprintf(tmp+ln, "=%s", value);
 637                                         name = tmp;
 638                                 }
 639                         } else {
 640                                 /* bash does not return an error when trying to export
 641                                  * an undefined variable.  Do likewise. */
 642                                 res = 1;
 643                         }
 644                 }
 645         }
 646         if (res<0)
 647                 perror_msg("export");
 648         else if(res==0)
 649                 res = set_local_var(name, 1);
 650         else
 651                 res = 0;
 652         free(name);
 653         return res;
 654 }
 655
 656 /* built-in 'fg' and 'bg' handler */
 657 static int builtin_fg_bg(struct child_prog *child)
 658 {
 659         int i, jobnum;
 660         struct pipe *pi=NULL;
 661
 662         if (!interactive)
 663                 return EXIT_FAILURE;
 664         /* If they gave us no args, assume they want the last backgrounded task */
 665         if (!child->argv[1]) {
 666                 for (pi = job_list; pi; pi = pi->next) {
 667                         if (pi->jobid == last_jobid) {
 668                                 break;
 669                         }
 670                 }
 671                 if (!pi) {
 672                         error_msg("%s: no current job", child->argv[0]);
 673                         return EXIT_FAILURE;
 674                 }
 675         } else {
 676                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 677                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 678                         return EXIT_FAILURE;
 679                 }
 680                 for (pi = job_list; pi; pi = pi->next) {
 681                         if (pi->jobid == jobnum) {
 682                                 break;
 683                         }
 684                 }
 685                 if (!pi) {
 686                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 687                         return EXIT_FAILURE;
 688                 }
 689         }
 690
 691         if (*child->argv[0] == 'f') {
 692                 /* Put the job into the foreground.  */
 693                 tcsetpgrp(shell_terminal, pi->pgrp);
 694         }
 695
 696         /* Restart the processes in the job */
 697         for (i = 0; i < pi->num_progs; i++)
 698                 pi->progs[i].is_stopped = 0;
 699
 700         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 701                 if (i == ESRCH) {
 702                         remove_bg_job(pi);
 703                 } else {
 704                         perror_msg("kill (SIGCONT)");
 705                 }
 706         }
 707
 708         pi->stopped_progs = 0;
 709         return EXIT_SUCCESS;
 710 }
 711
 712 /* built-in 'help' handler */
 713 static int builtin_help(struct child_prog *dummy)
 714 {
 715         struct built_in_command *x;
 716
 717         printf("\nBuilt-in commands:\n");
 718         printf("-------------------\n");
 719         for (x = bltins; x->cmd; x++) {
 720                 if (x->descr==NULL)
 721                         continue;
 722                 printf("%s\t%s\n", x->cmd, x->descr);
 723         }
 724         printf("\n\n");
 725         return EXIT_SUCCESS;
 726 }
 727
 728 /* built-in 'jobs' handler */
 729 static int builtin_jobs(struct child_prog *child)
 730 {
 731         struct pipe *job;
 732         char *status_string;
 733
 734         for (job = job_list; job; job = job->next) {
 735                 if (job->running_progs == job->stopped_progs)
 736                         status_string = "Stopped";
 737                 else
 738                         status_string = "Running";
 739
 740                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 741         }
 742         return EXIT_SUCCESS;
 743 }
 744
 745
 746 /* built-in 'pwd' handler */
 747 static int builtin_pwd(struct child_prog *dummy)
 748 {
 749         puts(set_cwd());
 750         return EXIT_SUCCESS;
 751 }
 752
 753 /* built-in 'read VAR' handler */
 754 static int builtin_read(struct child_prog *child)
 755 {
 756         int res;
 757
 758         if (child->argv[1]) {
 759                 char string[BUFSIZ];
 760                 char *var = 0;
 761
 762                 string[0] = 0;  /* In case stdin has only EOF */
 763                 /* read string */
 764                 fgets(string, sizeof(string), stdin);
 765                 chomp(string);
 766                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 767                 if(var) {
 768                         sprintf(var, "%s=%s", child->argv[1], string);
 769                         res = set_local_var(var, 0);
 770                 } else
 771                         res = -1;
 772                 if (res)
 773                         fprintf(stderr, "read: %m\n");
 774                 free(var);      /* So not move up to avoid breaking errno */
 775                 return res;
 776         } else {
 777                 do res=getchar(); while(res!='\n' && res!=EOF);
 778                 return 0;
 779         }
 780 }
 781
 782 /* built-in 'set VAR=value' handler */
 783 static int builtin_set(struct child_prog *child)
 784 {
 785         char *temp = child->argv[1];
 786         struct variables *e;
 787
 788         if (temp == NULL)
 789                 for(e = top_vars; e; e=e->next)
 790                         printf("%s=%s\n", e->name, e->value);
 791         else
 792                 set_local_var(temp, 0);
 793
 794                 return EXIT_SUCCESS;
 795 }
 796
 797
 798 /* Built-in 'shift' handler */
 799 static int builtin_shift(struct child_prog *child)
 800 {
 801         int n=1;
 802         if (child->argv[1]) {
 803                 n=atoi(child->argv[1]);
 804         }
 805         if (n>=0 && n<global_argc) {
 806                 /* XXX This probably breaks $0 */
 807                 global_argc -= n;
 808                 global_argv += n;
 809                 return EXIT_SUCCESS;
 810         } else {
 811                 return EXIT_FAILURE;
 812         }
 813 }
 814
 815 /* Built-in '.' handler (read-in and execute commands from file) */
 816 static int builtin_source(struct child_prog *child)
 817 {
 818         FILE *input;
 819         int status;
 820
 821         if (child->argv[1] == NULL)
 822                 return EXIT_FAILURE;
 823
 824         /* XXX search through $PATH is missing */
 825         input = fopen(child->argv[1], "r");
 826         if (!input) {
 827                 error_msg("Couldn't open file '%s'", child->argv[1]);
 828                 return EXIT_FAILURE;
 829         }
 830
 831         /* Now run the file */
 832         /* XXX argv and argc are broken; need to save old global_argv
 833          * (pointer only is OK!) on this stack frame,
 834          * set global_argv=child->argv+1, recurse, and restore. */
 835         mark_open(fileno(input));
 836         status = parse_file_outer(input);
 837         mark_closed(fileno(input));
 838         fclose(input);
 839         return (status);
 840 }
 841
 842 static int builtin_umask(struct child_prog *child)
 843 {
 844         mode_t new_umask;
 845         const char *arg = child->argv[1];
 846         char *end;
 847         if (arg) {
 848                 new_umask=strtoul(arg, &end, 8);
 849                 if (*end!='\0' || end == arg) {
 850                         return EXIT_FAILURE;
 851                 }
 852         } else {
 853                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 854         }
 855         umask(new_umask);
 856         return EXIT_SUCCESS;
 857 }
 858
 859 /* built-in 'unset VAR' handler */
 860 static int builtin_unset(struct child_prog *child)
 861 {
 862         /* bash returned already true */
 863         unset_local_var(child->argv[1]);
 864         return EXIT_SUCCESS;
 865 }
 866
 867 static int builtin_not_written(struct child_prog *child)
 868 {
 869         printf("builtin_%s not written\n",child->argv[0]);
 870         return EXIT_FAILURE;
 871 }
 872 #endif
 873
 874 static int b_check_space(o_string *o, int len)
 875 {
 876         /* It would be easy to drop a more restrictive policy
 877          * in here, such as setting a maximum string length */
 878         if (o->length + len > o->maxlen) {
 879                 char *old_data = o->data;
 880                 /* assert (data == NULL || o->maxlen != 0); */
 881                 o->maxlen += max(2*len, B_CHUNK);
 882                 o->data = realloc(o->data, 1 + o->maxlen);
 883                 if (o->data == NULL) {
 884                         free(old_data);
 885                 }
 886         }
 887         return o->data == NULL;
 888 }
 889
 890 static int b_addchr(o_string *o, int ch)
 891 {
 892         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 893         if (b_check_space(o, 1)) return B_NOSPAC;
 894         o->data[o->length] = ch;
 895         o->length++;
 896         o->data[o->length] = '\0';
 897         return 0;
 898 }
 899
 900 static void b_reset(o_string *o)
 901 {
 902         o->length = 0;
 903         o->nonnull = 0;
 904         if (o->data != NULL) *o->data = '\0';
 905 }
 906
 907 static void b_free(o_string *o)
 908 {
 909         b_reset(o);
 910         if (o->data != NULL) free(o->data);
 911         o->data = NULL;
 912         o->maxlen = 0;
 913 }
 914
 915 /* My analysis of quoting semantics tells me that state information
 916  * is associated with a destination, not a source.
 917  */
 918 static int b_addqchr(o_string *o, int ch, int quote)
 919 {
 920         if (quote && strchr("*?[\\",ch)) {
 921                 int rc;
 922                 rc = b_addchr(o, '\\');
 923                 if (rc) return rc;
 924         }
 925         return b_addchr(o, ch);
 926 }
 927
 928 /* belongs in utility.c */
 929 char *simple_itoa(unsigned int i)
 930 {
 931         /* 21 digits plus null terminator, good for 64-bit or smaller ints */
 932         static char local[22];
 933         char *p = &local[21];
 934         *p-- = '\0';
 935         do {
 936                 *p-- = '0' + i % 10;
 937                 i /= 10;
 938         } while (i > 0);
 939         return p + 1;
 940 }
 941
 942 static int b_adduint(o_string *o, unsigned int i)
 943 {
 944         int r;
 945         char *p = simple_itoa(i);
 946         /* no escape checking necessary */
 947         do r=b_addchr(o, *p++); while (r==0 && *p);
 948         return r;
 949 }
 950
 951 static int static_get(struct in_str *i)
 952 {
 953         int ch=*i->p++;
 954         if (ch=='\0') return EOF;
 955         return ch;
 956 }
 957
 958 static int static_peek(struct in_str *i)
 959 {
 960         return *i->p;
 961 }
 962
 963 #ifndef __U_BOOT__
 964 static inline void cmdedit_set_initial_prompt(void)
 965 {
 966 #ifndef BB_FEATURE_SH_FANCY_PROMPT
 967         PS1 = NULL;
 968 #else
 969         PS1 = getenv("PS1");
 970         if(PS1==0)
 971                 PS1 = "\\w \\$ ";
 972 #endif
 973 }
 974
 975 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 976 {
 977         debug_printf("setup_prompt_string %d ",promptmode);
 978 #ifndef BB_FEATURE_SH_FANCY_PROMPT
 979         /* Set up the prompt */
 980         if (promptmode == 1) {
 981                 if (PS1)
 982                         free(PS1);
 983                 PS1=xmalloc(strlen(cwd)+4);
 984                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 985                 *prompt_str = PS1;
 986         } else {
 987                 *prompt_str = PS2;
 988         }
 989 #else
 990         *prompt_str = (promptmode==1)? PS1 : PS2;
 991 #endif
 992         debug_printf("result %s\n",*prompt_str);
 993 }
 994 #endif
 995
 996 static void get_user_input(struct in_str *i)
 997 {
 998 #ifndef __U_BOOT__
 999         char *prompt_str;
1000         static char the_command[BUFSIZ];
1001
1002         setup_prompt_string(i->promptmode, &prompt_str);
1003 #ifdef BB_FEATURE_COMMAND_EDITING
1004         /*
1005          ** enable command line editing only while a command line
1006          ** is actually being read; otherwise, we'll end up bequeathing
1007          ** atexit() handlers and other unwanted stuff to our
1008          ** child processes (rob@sysgo.de)
1009          */
1010         cmdedit_read_input(prompt_str, the_command);
1011 #else
1012         fputs(prompt_str, stdout);
1013         fflush(stdout);
1014         the_command[0]=fgetc(i->file);
1015         the_command[1]='\0';
1016 #endif
1017         fflush(stdout);
1018         i->p = the_command;
1019 #else
1020         extern char console_buffer[CFG_CBSIZE];
1021         int n;
1022         static char the_command[CFG_CBSIZE];
1023
1024         i->__promptme = 1;
1025         if (i->promptmode == 1) {
1026                 n = readline(CFG_PROMPT);
1027         } else {
1028                 n = readline(CFG_PROMPT_HUSH_PS2);
1029         }
1030         if (n == -1 ) {
1031                 flag_repeat = 0;
1032                 i->__promptme = 0;
1033         }
1034         n = strlen(console_buffer);
1035         console_buffer[n] = '\n';
1036         console_buffer[n+1]= '\0';
1037         if (had_ctrlc()) flag_repeat = 0;
1038         clear_ctrlc();
1039         do_repeat = 0;
1040         if (i->promptmode == 1) {
1041                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1042                         strcpy(the_command,console_buffer);
1043                 }
1044                 else {
1045                         if (console_buffer[0] != '\n') {
1046                                 strcpy(the_command,console_buffer);
1047                                 flag_repeat = 1;
1048                         }
1049                         else {
1050                                 do_repeat = 1;
1051                         }
1052                 }
1053                 i->p = the_command;
1054         }
1055         else {
1056                 if (console_buffer[0] != '\n') {
1057                         if (strlen(the_command) + strlen(console_buffer)
1058                             < CFG_CBSIZE) {
1059                                 n = strlen(the_command);
1060                                 the_command[n-1] = ' ';
1061                                 strcpy(&the_command[n],console_buffer);
1062                         }
1063                         else {
1064                                 the_command[0] = '\n';
1065                                 the_command[1] = '\0';
1066                                 flag_repeat = 0;
1067                         }
1068                 }
1069                 if (i->__promptme == 0) {
1070                         the_command[0] = '\n';
1071                         the_command[1] = '\0';
1072                 }
1073                 i->p = console_buffer;
1074         }
1075 #endif
1076 }
1077
1078 /* This is the magic location that prints prompts
1079  * and gets data back from the user */
1080 static int file_get(struct in_str *i)
1081 {
1082         int ch;
1083
1084         ch = 0;
1085         /* If there is data waiting, eat it up */
1086         if (i->p && *i->p) {
1087                 ch=*i->p++;
1088         } else {
1089                 /* need to double check i->file because we might be doing something
1090                  * more complicated by now, like sourcing or substituting. */
1091 #ifndef __U_BOOT__
1092                 if (i->__promptme && interactive && i->file == stdin) {
1093                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1094 #else
1095                         while(! i->p  || strlen(i->p)==0 ) {
1096 #endif
1097                                 get_user_input(i);
1098                         }
1099                         i->promptmode=2;
1100 #ifndef __U_BOOT__
1101                         i->__promptme = 0;
1102 #endif
1103                         if (i->p && *i->p) {
1104                                 ch=*i->p++;
1105                         }
1106 #ifndef __U_BOOT__
1107                 } else {
1108                         ch = fgetc(i->file);
1109                 }
1110
1111 #endif
1112                 debug_printf("b_getch: got a %d\n", ch);
1113         }
1114 #ifndef __U_BOOT__
1115         if (ch == '\n') i->__promptme=1;
1116 #endif
1117         return ch;
1118 }
1119
1120 /* All the callers guarantee this routine will never be
1121  * used right after a newline, so prompting is not needed.
1122  */
1123 static int file_peek(struct in_str *i)
1124 {
1125 #ifndef __U_BOOT__
1126         if (i->p && *i->p) {
1127 #endif
1128                 return *i->p;
1129 #ifndef __U_BOOT__
1130         } else {
1131                 i->peek_buf[0] = fgetc(i->file);
1132                 i->peek_buf[1] = '\0';
1133                 i->p = i->peek_buf;
1134                 debug_printf("b_peek: got a %d\n", *i->p);
1135                 return *i->p;
1136         }
1137 #endif
1138 }
1139
1140 #ifndef __U_BOOT__
1141 static void setup_file_in_str(struct in_str *i, FILE *f)
1142 #else
1143 static void setup_file_in_str(struct in_str *i)
1144 #endif
1145 {
1146         i->peek = file_peek;
1147         i->get = file_get;
1148         i->__promptme=1;
1149         i->promptmode=1;
1150 #ifndef __U_BOOT__
1151         i->file = f;
1152 #endif
1153         i->p = NULL;
1154 }
1155
1156 static void setup_string_in_str(struct in_str *i, const char *s)
1157 {
1158         i->peek = static_peek;
1159         i->get = static_get;
1160         i->__promptme=1;
1161         i->promptmode=1;
1162         i->p = s;
1163 }
1164
1165 #ifndef __U_BOOT__
1166 static void mark_open(int fd)
1167 {
1168         struct close_me *new = xmalloc(sizeof(struct close_me));
1169         new->fd = fd;
1170         new->next = close_me_head;
1171         close_me_head = new;
1172 }
1173
1174 static void mark_closed(int fd)
1175 {
1176         struct close_me *tmp;
1177         if (close_me_head == NULL || close_me_head->fd != fd)
1178                 error_msg_and_die("corrupt close_me");
1179         tmp = close_me_head;
1180         close_me_head = close_me_head->next;
1181         free(tmp);
1182 }
1183
1184 static void close_all()
1185 {
1186         struct close_me *c;
1187         for (c=close_me_head; c; c=c->next) {
1188                 close(c->fd);
1189         }
1190         close_me_head = NULL;
1191 }
1192
1193 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1194  * and stderr if they are redirected. */
1195 static int setup_redirects(struct child_prog *prog, int squirrel[])
1196 {
1197         int openfd, mode;
1198         struct redir_struct *redir;
1199
1200         for (redir=prog->redirects; redir; redir=redir->next) {
1201                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1202                         /* something went wrong in the parse.  Pretend it didn't happen */
1203                         continue;
1204                 }
1205                 if (redir->dup == -1) {
1206                         mode=redir_table[redir->type].mode;
1207                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1208                         if (openfd < 0) {
1209                         /* this could get lost if stderr has been redirected, but
1210                            bash and ash both lose it as well (though zsh doesn't!) */
1211                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1212                                 return 1;
1213                         }
1214                 } else {
1215                         openfd = redir->dup;
1216                 }
1217
1218                 if (openfd != redir->fd) {
1219                         if (squirrel && redir->fd < 3) {
1220                                 squirrel[redir->fd] = dup(redir->fd);
1221                         }
1222                         if (openfd == -3) {
1223                                 close(openfd);
1224                         } else {
1225                                 dup2(openfd, redir->fd);
1226                                 if (redir->dup == -1)
1227                                         close (openfd);
1228                         }
1229                 }
1230         }
1231         return 0;
1232 }
1233
1234 static void restore_redirects(int squirrel[])
1235 {
1236         int i, fd;
1237         for (i=0; i<3; i++) {
1238                 fd = squirrel[i];
1239                 if (fd != -1) {
1240                         /* No error checking.  I sure wouldn't know what
1241                          * to do with an error if I found one! */
1242                         dup2(fd, i);
1243                         close(fd);
1244                 }
1245         }
1246 }
1247
1248 /* never returns */
1249 /* XXX no exit() here.  If you don't exec, use _exit instead.
1250  * The at_exit handlers apparently confuse the calling process,
1251  * in particular stdin handling.  Not sure why? */
1252 static void pseudo_exec(struct child_prog *child)
1253 {
1254         int i, rcode;
1255         char *p;
1256         struct built_in_command *x;
1257         if (child->argv) {
1258                 for (i=0; is_assignment(child->argv[i]); i++) {
1259                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1260                         p = insert_var_value(child->argv[i]);
1261                         putenv(strdup(p));
1262                         if (p != child->argv[i]) free(p);
1263                 }
1264                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1265                                         to exit, and therefore don't need to keep data
1266                                         structures consistent for free() use. */
1267                 /* If a variable is assigned in a forest, and nobody listens,
1268                  * was it ever really set?
1269                  */
1270                 if (child->argv[0] == NULL) {
1271                         _exit(EXIT_SUCCESS);
1272                 }
1273
1274                 /*
1275                  * Check if the command matches any of the builtins.
1276                  * Depending on context, this might be redundant.  But it's
1277                  * easier to waste a few CPU cycles than it is to figure out
1278                  * if this is one of those cases.
1279                  */
1280                 for (x = bltins; x->cmd; x++) {
1281                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1282                                 debug_printf("builtin exec %s\n", child->argv[0]);
1283                                 rcode = x->function(child);
1284                                 fflush(stdout);
1285                                 _exit(rcode);
1286                         }
1287                 }
1288
1289                 /* Check if the command matches any busybox internal commands
1290                  * ("applets") here.
1291                  * FIXME: This feature is not 100% safe, since
1292                  * BusyBox is not fully reentrant, so we have no guarantee the things
1293                  * from the .bss are still zeroed, or that things from .data are still
1294                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1295                  * really dislike relying on /proc for things.  We could exec ourself
1296                  * from global_argv[0], but if we are in a chroot, we may not be able
1297                  * to find ourself... */
1298 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1299                 {
1300                         int argc_l;
1301                         char** argv_l=child->argv;
1302                         char *name = child->argv[0];
1303
1304 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1305                         /* Following discussions from November 2000 on the busybox mailing
1306                          * list, the default configuration, (without
1307                          * get_last_path_component()) lets the user force use of an
1308                          * external command by specifying the full (with slashes) filename.
1309                          * If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then applets
1310                          * _aways_ override external commands, so if you want to run
1311                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1312                          * filesystem and is _not_ busybox.  Some systems may want this,
1313                          * most do not.  */
1314                         name = get_last_path_component(name);
1315 #endif
1316                         /* Count argc for use in a second... */
1317                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1318                         optind = 1;
1319                         debug_printf("running applet %s\n", name);
1320                         run_applet_by_name(name, argc_l, child->argv);
1321                 }
1322 #endif
1323                 debug_printf("exec of %s\n",child->argv[0]);
1324                 execvp(child->argv[0],child->argv);
1325                 perror_msg("couldn't exec: %s",child->argv[0]);
1326                 _exit(1);
1327         } else if (child->group) {
1328                 debug_printf("runtime nesting to group\n");
1329                 interactive=0;    /* crucial!!!! */
1330                 rcode = run_list_real(child->group);
1331                 /* OK to leak memory by not calling free_pipe_list,
1332                  * since this process is about to exit */
1333                 _exit(rcode);
1334         } else {
1335                 /* Can happen.  See what bash does with ">foo" by itself. */
1336                 debug_printf("trying to pseudo_exec null command\n");
1337                 _exit(EXIT_SUCCESS);
1338         }
1339 }
1340
1341 static void insert_bg_job(struct pipe *pi)
1342 {
1343         struct pipe *thejob;
1344
1345         /* Linear search for the ID of the job to use */
1346         pi->jobid = 1;
1347         for (thejob = job_list; thejob; thejob = thejob->next)
1348                 if (thejob->jobid >= pi->jobid)
1349                         pi->jobid = thejob->jobid + 1;
1350
1351         /* add thejob to the list of running jobs */
1352         if (!job_list) {
1353                 thejob = job_list = xmalloc(sizeof(*thejob));
1354         } else {
1355                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1356                 thejob->next = xmalloc(sizeof(*thejob));
1357                 thejob = thejob->next;
1358         }
1359
1360         /* physically copy the struct job */
1361         memcpy(thejob, pi, sizeof(struct pipe));
1362         thejob->next = NULL;
1363         thejob->running_progs = thejob->num_progs;
1364         thejob->stopped_progs = 0;
1365         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1366
1367         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1368         {
1369                 char *bar=thejob->text;
1370                 char **foo=pi->progs[0].argv;
1371                 while(foo && *foo) {
1372                         bar += sprintf(bar, "%s ", *foo++);
1373                 }
1374         }
1375
1376         /* we don't wait for background thejobs to return -- append it
1377            to the list of backgrounded thejobs and leave it alone */
1378         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1379         last_bg_pid = thejob->progs[0].pid;
1380         last_jobid = thejob->jobid;
1381 }
1382
1383 /* remove a backgrounded job */
1384 static void remove_bg_job(struct pipe *pi)
1385 {
1386         struct pipe *prev_pipe;
1387
1388         if (pi == job_list) {
1389                 job_list = pi->next;
1390         } else {
1391                 prev_pipe = job_list;
1392                 while (prev_pipe->next != pi)
1393                         prev_pipe = prev_pipe->next;
1394                 prev_pipe->next = pi->next;
1395         }
1396         if (job_list)
1397                 last_jobid = job_list->jobid;
1398         else
1399                 last_jobid = 0;
1400
1401         pi->stopped_progs = 0;
1402         free_pipe(pi, 0);
1403         free(pi);
1404 }
1405
1406 /* Checks to see if any processes have exited -- if they
1407    have, figure out why and see if a job has completed */
1408 static int checkjobs(struct pipe* fg_pipe)
1409 {
1410         int attributes;
1411         int status;
1412         int prognum = 0;
1413         struct pipe *pi;
1414         pid_t childpid;
1415
1416         attributes = WUNTRACED;
1417         if (fg_pipe==NULL) {
1418                 attributes |= WNOHANG;
1419         }
1420
1421         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1422                 if (fg_pipe) {
1423                         int i, rcode = 0;
1424                         for (i=0; i < fg_pipe->num_progs; i++) {
1425                                 if (fg_pipe->progs[i].pid == childpid) {
1426                                         if (i==fg_pipe->num_progs-1)
1427                                                 rcode=WEXITSTATUS(status);
1428                                         (fg_pipe->num_progs)--;
1429                                         return(rcode);
1430                                 }
1431                         }
1432                 }
1433
1434                 for (pi = job_list; pi; pi = pi->next) {
1435                         prognum = 0;
1436                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1437                                 prognum++;
1438                         }
1439                         if (prognum < pi->num_progs)
1440                                 break;
1441                 }
1442
1443                 if(pi==NULL) {
1444                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1445                         continue;
1446                 }
1447
1448                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1449                         /* child exited */
1450                         pi->running_progs--;
1451                         pi->progs[prognum].pid = 0;
1452
1453                         if (!pi->running_progs) {
1454                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1455                                 remove_bg_job(pi);
1456                         }
1457                 } else {
1458                         /* child stopped */
1459                         pi->stopped_progs++;
1460                         pi->progs[prognum].is_stopped = 1;
1461
1462 #if 0
1463                         /* Printing this stuff is a pain, since it tends to
1464                          * overwrite the prompt an inconveinient moments.  So
1465                          * don't do that.  */
1466                         if (pi->stopped_progs == pi->num_progs) {
1467                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1468                         }
1469 #endif
1470                 }
1471         }
1472
1473         if (childpid == -1 && errno != ECHILD)
1474                 perror_msg("waitpid");
1475
1476         /* move the shell to the foreground */
1477         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1478         /*      perror_msg("tcsetpgrp-2"); */
1479         return -1;
1480 }
1481
1482 /* Figure out our controlling tty, checking in order stderr,
1483  * stdin, and stdout.  If check_pgrp is set, also check that
1484  * we belong to the foreground process group associated with
1485  * that tty.  The value of shell_terminal is needed in order to call
1486  * tcsetpgrp(shell_terminal, ...); */
1487 void controlling_tty(int check_pgrp)
1488 {
1489         pid_t curpgrp;
1490
1491         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1492                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1493                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1494                 goto shell_terminal_error;
1495
1496         if (check_pgrp && curpgrp != getpgid(0))
1497                 goto shell_terminal_error;
1498
1499         return;
1500
1501 shell_terminal_error:
1502                 shell_terminal = -1;
1503                 return;
1504 }
1505 #endif
1506
1507 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1508  * to finish.  See checkjobs().
1509  *
1510  * return code is normally -1, when the caller has to wait for children
1511  * to finish to determine the exit status of the pipe.  If the pipe
1512  * is a simple builtin command, however, the action is done by the
1513  * time run_pipe_real returns, and the exit code is provided as the
1514  * return value.
1515  *
1516  * The input of the pipe is always stdin, the output is always
1517  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1518  * because it tries to avoid running the command substitution in
1519  * subshell, when that is in fact necessary.  The subshell process
1520  * now has its stdout directed to the input of the appropriate pipe,
1521  * so this routine is noticeably simpler.
1522  */
1523 static int run_pipe_real(struct pipe *pi)
1524 {
1525         int i;
1526 #ifndef __U_BOOT__
1527         int nextin, nextout;
1528         int pipefds[2];                         /* pipefds[0] is for reading */
1529         struct child_prog *child;
1530         struct built_in_command *x;
1531         char *p;
1532 #else
1533         int nextin;
1534         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1535         struct child_prog *child;
1536         cmd_tbl_t *cmdtp;
1537         char *p;
1538 #endif
1539
1540         nextin = 0;
1541 #ifndef __U_BOOT__
1542         pi->pgrp = -1;
1543 #endif
1544
1545         /* Check if this is a simple builtin (not part of a pipe).
1546          * Builtins within pipes have to fork anyway, and are handled in
1547          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1548          */
1549         if (pi->num_progs == 1) child = & (pi->progs[0]);
1550 #ifndef __U_BOOT__
1551         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1552                 int squirrel[] = {-1, -1, -1};
1553                 int rcode;
1554                 debug_printf("non-subshell grouping\n");
1555                 setup_redirects(child, squirrel);
1556                 /* XXX could we merge code with following builtin case,
1557                  * by creating a pseudo builtin that calls run_list_real? */
1558                 rcode = run_list_real(child->group);
1559                 restore_redirects(squirrel);
1560 #else
1561                 if (pi->num_progs == 1 && child->group) {
1562                 int rcode;
1563                 debug_printf("non-subshell grouping\n");
1564                 rcode = run_list_real(child->group);
1565 #endif
1566                 return rcode;
1567         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1568                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1569                 if (i!=0 && child->argv[i]==NULL) {
1570                         /* assignments, but no command: set the local environment */
1571                         for (i=0; child->argv[i]!=NULL; i++) {
1572
1573                                 /* Ok, this case is tricky.  We have to decide if this is a
1574                                  * local variable, or an already exported variable.  If it is
1575                                  * already exported, we have to export the new value.  If it is
1576                                  * not exported, we need only set this as a local variable.
1577                                  * This junk is all to decide whether or not to export this
1578                                  * variable. */
1579                                 int export_me=0;
1580                                 char *name, *value;
1581                                 name = xstrdup(child->argv[i]);
1582                                 debug_printf("Local environment set: %s\n", name);
1583                                 value = strchr(name, '=');
1584                                 if (value)
1585                                         *value=0;
1586 #ifndef __U_BOOT__
1587                                 if ( get_local_var(name)) {
1588                                         export_me=1;
1589                                 }
1590 #endif
1591                                 free(name);
1592                                 p = insert_var_value(child->argv[i]);
1593                                 set_local_var(p, export_me);
1594                                 if (p != child->argv[i]) free(p);
1595                         }
1596                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1597                 }
1598                 for (i = 0; is_assignment(child->argv[i]); i++) {
1599                         p = insert_var_value(child->argv[i]);
1600 #ifndef __U_BOOT__
1601                         putenv(strdup(p));
1602 #else
1603                         set_local_var(p, 0);
1604 #endif
1605                         if (p != child->argv[i]) {
1606                                 child->sp--;
1607                                 free(p);
1608                         }
1609                 }
1610                 if (child->sp) {
1611                         char * str = NULL;
1612
1613                         str = make_string((child->argv + i));
1614                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1615                         free(str);
1616                         return last_return_code;
1617                 }
1618 #ifndef __U_BOOT__
1619                 for (x = bltins; x->cmd; x++) {
1620                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1621                                 int squirrel[] = {-1, -1, -1};
1622                                 int rcode;
1623                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1624                                         debug_printf("magic exec\n");
1625                                         setup_redirects(child,NULL);
1626                                         return EXIT_SUCCESS;
1627                                 }
1628                                 debug_printf("builtin inline %s\n", child->argv[0]);
1629                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1630                                  * This is perfect for work that comes after exec().
1631                                  * Is it really safe for inline use?  Experimentally,
1632                                  * things seem to work with glibc. */
1633                                 setup_redirects(child, squirrel);
1634 #else
1635                         /* check ";", because ,example , argv consist from
1636                          * "help;flinfo" must not execute
1637                          */
1638                         if (strchr(child->argv[i], ';')) {
1639                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1640                                         child->argv[i]);
1641                                 return -1;
1642                         }
1643                         /* Look up command in command table */
1644                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1645                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1646                                 return -1;      /* give up after bad command */
1647                         } else {
1648                                 int rcode;
1649 #if (CONFIG_COMMANDS & CFG_CMD_BOOTD)
1650                                 /* avoid "bootd" recursion */
1651                                 if (cmdtp->cmd == do_bootd) {
1652                                         if (flag & CMD_FLAG_BOOTD) {
1653                                                 printf ("'bootd' recursion detected\n");
1654                                                 return -1;
1655                                         }
1656                                 else
1657                                         flag |= CMD_FLAG_BOOTD;
1658                                 }
1659 #endif  /* CFG_CMD_BOOTD */
1660                                 /* found - check max args */
1661                                 if ((child->argc - i) > cmdtp->maxargs) {
1662                                         printf ("Usage:\n%s\n", cmdtp->usage);
1663                                         return -1;
1664                                 }
1665 #endif
1666                                 child->argv+=i;  /* XXX horrible hack */
1667 #ifndef __U_BOOT__
1668                                 rcode = x->function(child);
1669 #else
1670                                 /* OK - call function to do the command */
1671                                 rcode = (cmdtp->cmd)
1672                                         (cmdtp, flag,child->argc-i,&child->argv[i]);
1673                                 if ( !cmdtp->repeatable )
1674                                         flag_repeat = 0;
1675 #endif
1676                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1677 #ifndef __U_BOOT__
1678                                 restore_redirects(squirrel);
1679 #endif
1680                                 return rcode;
1681                         }
1682                 }
1683 #ifndef __U_BOOT__
1684         }
1685
1686         for (i = 0; i < pi->num_progs; i++) {
1687                 child = & (pi->progs[i]);
1688
1689                 /* pipes are inserted between pairs of commands */
1690                 if ((i + 1) < pi->num_progs) {
1691                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1692                         nextout = pipefds[1];
1693                 } else {
1694                         nextout=1;
1695                         pipefds[0] = -1;
1696                 }
1697
1698                 /* XXX test for failed fork()? */
1699                 if (!(child->pid = fork())) {
1700                         /* Set the handling for job control signals back to the default.  */
1701                         signal(SIGINT, SIG_DFL);
1702                         signal(SIGQUIT, SIG_DFL);
1703                         signal(SIGTERM, SIG_DFL);
1704                         signal(SIGTSTP, SIG_DFL);
1705                         signal(SIGTTIN, SIG_DFL);
1706                         signal(SIGTTOU, SIG_DFL);
1707                         signal(SIGCHLD, SIG_DFL);
1708
1709                         close_all();
1710
1711                         if (nextin != 0) {
1712                                 dup2(nextin, 0);
1713                                 close(nextin);
1714                         }
1715                         if (nextout != 1) {
1716                                 dup2(nextout, 1);
1717                                 close(nextout);
1718                         }
1719                         if (pipefds[0]!=-1) {
1720                                 close(pipefds[0]);  /* opposite end of our output pipe */
1721                         }
1722
1723                         /* Like bash, explicit redirects override pipes,
1724                          * and the pipe fd is available for dup'ing. */
1725                         setup_redirects(child,NULL);
1726
1727                         if (interactive && pi->followup!=PIPE_BG) {
1728                                 /* If we (the child) win the race, put ourselves in the process
1729                                  * group whose leader is the first process in this pipe. */
1730                                 if (pi->pgrp < 0) {
1731                                         pi->pgrp = getpid();
1732                                 }
1733                                 if (setpgid(0, pi->pgrp) == 0) {
1734                                         tcsetpgrp(2, pi->pgrp);
1735                                 }
1736                         }
1737
1738                         pseudo_exec(child);
1739                 }
1740
1741
1742                 /* put our child in the process group whose leader is the
1743                    first process in this pipe */
1744                 if (pi->pgrp < 0) {
1745                         pi->pgrp = child->pid;
1746                 }
1747                 /* Don't check for errors.  The child may be dead already,
1748                  * in which case setpgid returns error code EACCES. */
1749                 setpgid(child->pid, pi->pgrp);
1750
1751                 if (nextin != 0)
1752                         close(nextin);
1753                 if (nextout != 1)
1754                         close(nextout);
1755
1756                 /* If there isn't another process, nextin is garbage
1757                    but it doesn't matter */
1758                 nextin = pipefds[0];
1759         }
1760 #endif
1761         return -1;
1762 }
1763
1764 static int run_list_real(struct pipe *pi)
1765 {
1766         char *save_name = NULL;
1767         char **list = NULL;
1768         char **save_list = NULL;
1769         struct pipe *rpipe;
1770         int flag_rep = 0;
1771 #ifndef __U_BOOT__
1772         int save_num_progs;
1773 #endif
1774         int rcode=0, flag_skip=1;
1775         int flag_restore = 0;
1776         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1777         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1778         /* check syntax for "for" */
1779         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1780                 if ((rpipe->r_mode == RES_IN ||
1781                     rpipe->r_mode == RES_FOR) &&
1782                     (rpipe->next == NULL)) {
1783                                 syntax();
1784 #ifdef __U_BOOT__
1785                                 flag_repeat = 0;
1786 #endif
1787                                 return 1;
1788                 }
1789                 if ((rpipe->r_mode == RES_IN &&
1790                         (rpipe->next->r_mode == RES_IN &&
1791                         rpipe->next->progs->argv != NULL))||
1792                         (rpipe->r_mode == RES_FOR &&
1793                         rpipe->next->r_mode != RES_IN)) {
1794                                 syntax();
1795 #ifdef __U_BOOT__
1796                                 flag_repeat = 0;
1797 #endif
1798                                 return 1;
1799                 }
1800         }
1801         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1802                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1803                         pi->r_mode == RES_FOR) {
1804 #ifdef __U_BOOT__
1805                                 /* check Ctrl-C */
1806                                 ctrlc();
1807                                 if ((had_ctrlc())) {
1808                                         return 1;
1809                                 }
1810 #endif
1811                                 flag_restore = 0;
1812                                 if (!rpipe) {
1813                                         flag_rep = 0;
1814                                         rpipe = pi;
1815                                 }
1816                 }
1817                 rmode = pi->r_mode;
1818                 debug_printf("rmode=%d  if_code=%d  next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1819                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1820                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1821                         continue;
1822                 }
1823                 flag_skip = 1;
1824                 skip_more_in_this_rmode = RES_XXXX;
1825                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1826                 if (rmode == RES_THEN &&  if_code) continue;
1827                 if (rmode == RES_ELSE && !if_code) continue;
1828                 if (rmode == RES_ELIF && !if_code) continue;
1829                 if (rmode == RES_FOR && pi->num_progs) {
1830                         if (!list) {
1831                                 /* if no variable values after "in" we skip "for" */
1832                                 if (!pi->next->progs->argv) continue;
1833                                 /* create list of variable values */
1834                                 list = make_list_in(pi->next->progs->argv,
1835                                         pi->progs->argv[0]);
1836                                 save_list = list;
1837                                 save_name = pi->progs->argv[0];
1838                                 pi->progs->argv[0] = NULL;
1839                                 flag_rep = 1;
1840                         }
1841                         if (!(*list)) {
1842                                 free(pi->progs->argv[0]);
1843                                 free(save_list);
1844                                 list = NULL;
1845                                 flag_rep = 0;
1846                                 pi->progs->argv[0] = save_name;
1847 #ifndef __U_BOOT__
1848                                 pi->progs->glob_result.gl_pathv[0] =
1849                                         pi->progs->argv[0];
1850 #endif
1851                                 continue;
1852                         } else {
1853                                 /* insert new value from list for variable */
1854                                 if (pi->progs->argv[0])
1855                                         free(pi->progs->argv[0]);
1856                                 pi->progs->argv[0] = *list++;
1857 #ifndef __U_BOOT__
1858                                 pi->progs->glob_result.gl_pathv[0] =
1859                                         pi->progs->argv[0];
1860 #endif
1861                         }
1862                 }
1863                 if (rmode == RES_IN) continue;
1864                 if (rmode == RES_DO) {
1865                         if (!flag_rep) continue;
1866                 }
1867                 if ((rmode == RES_DONE)) {
1868                         if (flag_rep) {
1869                                 flag_restore = 1;
1870                         } else {
1871                                 rpipe = NULL;
1872                         }
1873                 }
1874                 if (pi->num_progs == 0) continue;
1875 #ifndef __U_BOOT__
1876                 save_num_progs = pi->num_progs; /* save number of programs */
1877 #endif
1878                 rcode = run_pipe_real(pi);
1879                 debug_printf("run_pipe_real returned %d\n",rcode);
1880 #ifndef __U_BOOT__
1881                 if (rcode!=-1) {
1882                         /* We only ran a builtin: rcode was set by the return value
1883                          * of run_pipe_real(), and we don't need to wait for anything. */
1884                 } else if (pi->followup==PIPE_BG) {
1885                         /* XXX check bash's behavior with nontrivial pipes */
1886                         /* XXX compute jobid */
1887                         /* XXX what does bash do with attempts to background builtins? */
1888                         insert_bg_job(pi);
1889                         rcode = EXIT_SUCCESS;
1890                 } else {
1891                         if (interactive) {
1892                                 /* move the new process group into the foreground */
1893                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1894                                         perror_msg("tcsetpgrp-3");
1895                                 rcode = checkjobs(pi);
1896                                 /* move the shell to the foreground */
1897                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1898                                         perror_msg("tcsetpgrp-4");
1899                         } else {
1900                                 rcode = checkjobs(pi);
1901                         }
1902                         debug_printf("checkjobs returned %d\n",rcode);
1903                 }
1904                 last_return_code=rcode;
1905 #else
1906                 last_return_code=(rcode == 0) ? 0 : 1;
1907 #endif
1908 #ifndef __U_BOOT__
1909                 pi->num_progs = save_num_progs; /* restore number of programs */
1910 #endif
1911                 if ( rmode == RES_IF || rmode == RES_ELIF )
1912                         next_if_code=rcode;  /* can be overwritten a number of times */
1913                 if (rmode == RES_WHILE)
1914                         flag_rep = !last_return_code;
1915                 if (rmode == RES_UNTIL)
1916                         flag_rep = last_return_code;
1917                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1918                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1919                         skip_more_in_this_rmode=rmode;
1920 #ifndef __U_BOOT__
1921                 checkjobs(NULL);
1922 #endif
1923         }
1924         return rcode;
1925 }
1926
1927 /* broken, of course, but OK for testing */
1928 static char *indenter(int i)
1929 {
1930         static char blanks[]="                                    ";
1931         return &blanks[sizeof(blanks)-i-1];
1932 }
1933
1934 /* return code is the exit status of the pipe */
1935 static int free_pipe(struct pipe *pi, int indent)
1936 {
1937         char **p;
1938         struct child_prog *child;
1939 #ifndef __U_BOOT__
1940         struct redir_struct *r, *rnext;
1941 #endif
1942         int a, i, ret_code=0;
1943         char *ind = indenter(indent);
1944
1945 #ifndef __U_BOOT__
1946         if (pi->stopped_progs > 0)
1947                 return ret_code;
1948         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1949 #endif
1950         for (i=0; i<pi->num_progs; i++) {
1951                 child = &pi->progs[i];
1952                 final_printf("%s  command %d:\n",ind,i);
1953                 if (child->argv) {
1954                         for (a=0,p=child->argv; *p; a++,p++) {
1955                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1956                         }
1957 #ifndef __U_BOOT__
1958                         globfree(&child->glob_result);
1959 #else
1960                         for (a = child->argc;a >= 0;a--) {
1961                                 free(child->argv[a]);
1962                         }
1963                                         free(child->argv);
1964                         child->argc = 0;
1965 #endif
1966                         child->argv=NULL;
1967                 } else if (child->group) {
1968 #ifndef __U_BOOT__
1969                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1970 #endif
1971                         ret_code = free_pipe_list(child->group,indent+3);
1972                         final_printf("%s   end group\n",ind);
1973                 } else {
1974                         final_printf("%s   (nil)\n",ind);
1975                 }
1976 #ifndef __U_BOOT__
1977                 for (r=child->redirects; r; r=rnext) {
1978                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1979                         if (r->dup == -1) {
1980                                 /* guard against the case >$FOO, where foo is unset or blank */
1981                                 if (r->word.gl_pathv) {
1982                                         final_printf(" %s\n", *r->word.gl_pathv);
1983                                         globfree(&r->word);
1984                                 }
1985                         } else {
1986                                 final_printf("&%d\n", r->dup);
1987                         }
1988                         rnext=r->next;
1989                         free(r);
1990                 }
1991                 child->redirects=NULL;
1992 #endif
1993         }
1994         free(pi->progs);   /* children are an array, they get freed all at once */
1995         pi->progs=NULL;
1996         return ret_code;
1997 }
1998
1999 static int free_pipe_list(struct pipe *head, int indent)
2000 {
2001         int rcode=0;   /* if list has no members */
2002         struct pipe *pi, *next;
2003         char *ind = indenter(indent);
2004         for (pi=head; pi; pi=next) {
2005                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2006                 rcode = free_pipe(pi, indent);
2007                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2008                 next=pi->next;
2009                 pi->next=NULL;
2010                 free(pi);
2011         }
2012         return rcode;
2013 }
2014
2015 /* Select which version we will use */
2016 static int run_list(struct pipe *pi)
2017 {
2018         int rcode=0;
2019 #ifndef __U_BOOT__
2020         if (fake_mode==0) {
2021 #endif
2022                 rcode = run_list_real(pi);
2023 #ifndef __U_BOOT__
2024         }
2025 #endif
2026         /* free_pipe_list has the side effect of clearing memory
2027          * In the long run that function can be merged with run_list_real,
2028          * but doing that now would hobble the debugging effort. */
2029         free_pipe_list(pi,0);
2030         return rcode;
2031 }
2032
2033 /* The API for glob is arguably broken.  This routine pushes a non-matching
2034  * string into the output structure, removing non-backslashed backslashes.
2035  * If someone can prove me wrong, by performing this function within the
2036  * original glob(3) api, feel free to rewrite this routine into oblivion.
2037  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2038  * XXX broken if the last character is '\\', check that before calling.
2039  */
2040 #ifndef __U_BOOT__
2041 static int globhack(const char *src, int flags, glob_t *pglob)
2042 {
2043         int cnt=0, pathc;
2044         const char *s;
2045         char *dest;
2046         for (cnt=1, s=src; s && *s; s++) {
2047                 if (*s == '\\') s++;
2048                 cnt++;
2049         }
2050         dest = malloc(cnt);
2051         if (!dest) return GLOB_NOSPACE;
2052         if (!(flags & GLOB_APPEND)) {
2053                 pglob->gl_pathv=NULL;
2054                 pglob->gl_pathc=0;
2055                 pglob->gl_offs=0;
2056                 pglob->gl_offs=0;
2057         }
2058         pathc = ++pglob->gl_pathc;
2059         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2060         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2061         pglob->gl_pathv[pathc-1]=dest;
2062         pglob->gl_pathv[pathc]=NULL;
2063         for (s=src; s && *s; s++, dest++) {
2064                 if (*s == '\\') s++;
2065                 *dest = *s;
2066         }
2067         *dest='\0';
2068         return 0;
2069 }
2070
2071 /* XXX broken if the last character is '\\', check that before calling */
2072 static int glob_needed(const char *s)
2073 {
2074         for (; *s; s++) {
2075                 if (*s == '\\') s++;
2076                 if (strchr("*[?",*s)) return 1;
2077         }
2078         return 0;
2079 }
2080
2081 #if 0
2082 static void globprint(glob_t *pglob)
2083 {
2084         int i;
2085         debug_printf("glob_t at %p:\n", pglob);
2086         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2087                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2088         for (i=0; i<pglob->gl_pathc; i++)
2089                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2090                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2091 }
2092 #endif
2093
2094 static int xglob(o_string *dest, int flags, glob_t *pglob)
2095 {
2096         int gr;
2097
2098         /* short-circuit for null word */
2099         /* we can code this better when the debug_printf's are gone */
2100         if (dest->length == 0) {
2101                 if (dest->nonnull) {
2102                         /* bash man page calls this an "explicit" null */
2103                         gr = globhack(dest->data, flags, pglob);
2104                         debug_printf("globhack returned %d\n",gr);
2105                 } else {
2106                         return 0;
2107                 }
2108         } else if (glob_needed(dest->data)) {
2109                 gr = glob(dest->data, flags, NULL, pglob);
2110                 debug_printf("glob returned %d\n",gr);
2111                 if (gr == GLOB_NOMATCH) {
2112                         /* quote removal, or more accurately, backslash removal */
2113                         gr = globhack(dest->data, flags, pglob);
2114                         debug_printf("globhack returned %d\n",gr);
2115                 }
2116         } else {
2117                 gr = globhack(dest->data, flags, pglob);
2118                 debug_printf("globhack returned %d\n",gr);
2119         }
2120         if (gr == GLOB_NOSPACE)
2121                 error_msg_and_die("out of memory during glob");
2122         if (gr != 0) { /* GLOB_ABORTED ? */
2123                 error_msg("glob(3) error %d",gr);
2124         }
2125         /* globprint(glob_target); */
2126         return gr;
2127 }
2128 #endif
2129
2130 /* This is used to get/check local shell variables */
2131 static char *get_local_var(const char *s)
2132 {
2133         struct variables *cur;
2134
2135         if (!s)
2136                 return NULL;
2137         for (cur = top_vars; cur; cur=cur->next)
2138                 if(strcmp(cur->name, s)==0)
2139                         return cur->value;
2140         return NULL;
2141 }
2142
2143 /* This is used to set local shell variables
2144    flg_export==0 if only local (not exporting) variable
2145    flg_export==1 if "new" exporting environ
2146    flg_export>1  if current startup environ (not call putenv()) */
2147 static int set_local_var(const char *s, int flg_export)
2148 {
2149         char *name, *value;
2150         int result=0;
2151         struct variables *cur;
2152
2153         name=strdup(s);
2154
2155 #ifdef __U_BOOT__
2156         if (getenv(name) != NULL) {
2157                 printf ("ERROR: "
2158                                 "There is a global environmet variable with the same name.\n");
2159                 return -1;
2160         }
2161 #endif
2162         /* Assume when we enter this function that we are already in
2163          * NAME=VALUE format.  So the first order of business is to
2164          * split 's' on the '=' into 'name' and 'value' */
2165         value = strchr(name, '=');
2166         if (value==0 && ++value==0) {
2167                 free(name);
2168                 return -1;
2169         }
2170         *value++ = 0;
2171
2172         for(cur = top_vars; cur; cur = cur->next) {
2173                 if(strcmp(cur->name, name)==0)
2174                         break;
2175         }
2176
2177         if(cur) {
2178                 if(strcmp(cur->value, value)==0) {
2179                         if(flg_export>0 && cur->flg_export==0)
2180                                 cur->flg_export=flg_export;
2181                         else
2182                                 result++;
2183                 } else {
2184                         if(cur->flg_read_only) {
2185                                 error_msg("%s: readonly variable", name);
2186                                 result = -1;
2187                         } else {
2188                                 if(flg_export>0 || cur->flg_export>1)
2189                                         cur->flg_export=1;
2190                                 free(cur->value);
2191
2192                                 cur->value = strdup(value);
2193                         }
2194                 }
2195         } else {
2196                 cur = malloc(sizeof(struct variables));
2197                 if(!cur) {
2198                         result = -1;
2199                 } else {
2200                         cur->name = strdup(name);
2201                         if(cur->name == 0) {
2202                                 free(cur);
2203                                 result = -1;
2204                         } else {
2205                                 struct variables *bottom = top_vars;
2206                                 cur->value = strdup(value);
2207                                 cur->next = 0;
2208                                 cur->flg_export = flg_export;
2209                                 cur->flg_read_only = 0;
2210                                 while(bottom->next) bottom=bottom->next;
2211                                 bottom->next = cur;
2212                         }
2213                 }
2214         }
2215
2216 #ifndef __U_BOOT__
2217         if(result==0 && cur->flg_export==1) {
2218                 *(value-1) = '=';
2219                 result = putenv(name);
2220         } else {
2221 #endif
2222                 free(name);
2223 #ifndef __U_BOOT__
2224                 if(result>0)            /* equivalent to previous set */
2225                         result = 0;
2226         }
2227 #endif
2228         return result;
2229 }
2230
2231 #ifndef __U_BOOT__
2232 static void unset_local_var(const char *name)
2233 {
2234         struct variables *cur;
2235
2236         if (name) {
2237                 for (cur = top_vars; cur; cur=cur->next) {
2238                         if(strcmp(cur->name, name)==0)
2239                                 break;
2240                 }
2241                 if(cur!=0) {
2242                         struct variables *next = top_vars;
2243                         if(cur->flg_read_only) {
2244                                 error_msg("%s: readonly variable", name);
2245                                 return;
2246                         } else {
2247                                 if(cur->flg_export)
2248                                         unsetenv(cur->name);
2249                                 free(cur->name);
2250                                 free(cur->value);
2251                                 while (next->next != cur)
2252                                         next = next->next;
2253                                 next->next = cur->next;
2254                         }
2255                         free(cur);
2256                 }
2257         }
2258 }
2259 #endif
2260
2261 static int is_assignment(const char *s)
2262 {
2263         if (s==NULL || !isalpha(*s)) return 0;
2264         ++s;
2265         while(isalnum(*s) || *s=='_') ++s;
2266         return *s=='=';
2267 }
2268
2269 #ifndef __U_BOOT__
2270 /* the src parameter allows us to peek forward to a possible &n syntax
2271  * for file descriptor duplication, e.g., "2>&1".
2272  * Return code is 0 normally, 1 if a syntax error is detected in src.
2273  * Resource errors (in xmalloc) cause the process to exit */
2274 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2275         struct in_str *input)
2276 {
2277         struct child_prog *child=ctx->child;
2278         struct redir_struct *redir = child->redirects;
2279         struct redir_struct *last_redir=NULL;
2280
2281         /* Create a new redir_struct and drop it onto the end of the linked list */
2282         while(redir) {
2283                 last_redir=redir;
2284                 redir=redir->next;
2285         }
2286         redir = xmalloc(sizeof(struct redir_struct));
2287         redir->next=NULL;
2288         redir->word.gl_pathv=NULL;
2289         if (last_redir) {
2290                 last_redir->next=redir;
2291         } else {
2292                 child->redirects=redir;
2293         }
2294
2295         redir->type=style;
2296         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2297
2298         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2299
2300         /* Check for a '2>&1' type redirect */
2301         redir->dup = redirect_dup_num(input);
2302         if (redir->dup == -2) return 1;  /* syntax error */
2303         if (redir->dup != -1) {
2304                 /* Erik had a check here that the file descriptor in question
2305                  * is legit; I postpone that to "run time"
2306                  * A "-" representation of "close me" shows up as a -3 here */
2307                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2308         } else {
2309                 /* We do _not_ try to open the file that src points to,
2310                  * since we need to return and let src be expanded first.
2311                  * Set ctx->pending_redirect, so we know what to do at the
2312                  * end of the next parsed word.
2313                  */
2314                 ctx->pending_redirect = redir;
2315         }
2316         return 0;
2317 }
2318 #endif
2319
2320 struct pipe *new_pipe(void) {
2321         struct pipe *pi;
2322         pi = xmalloc(sizeof(struct pipe));
2323         pi->num_progs = 0;
2324         pi->progs = NULL;
2325         pi->next = NULL;
2326         pi->followup = 0;  /* invalid */
2327         return pi;
2328 }
2329
2330 static void initialize_context(struct p_context *ctx)
2331 {
2332         ctx->pipe=NULL;
2333 #ifndef __U_BOOT__
2334         ctx->pending_redirect=NULL;
2335 #endif
2336         ctx->child=NULL;
2337         ctx->list_head=new_pipe();
2338         ctx->pipe=ctx->list_head;
2339         ctx->w=RES_NONE;
2340         ctx->stack=NULL;
2341 #ifdef __U_BOOT__
2342         ctx->old_flag=0;
2343 #endif
2344         done_command(ctx);   /* creates the memory for working child */
2345 }
2346
2347 /* normal return is 0
2348  * if a reserved word is found, and processed, return 1
2349  * should handle if, then, elif, else, fi, for, while, until, do, done.
2350  * case, function, and select are obnoxious, save those for later.
2351  */
2352 int reserved_word(o_string *dest, struct p_context *ctx)
2353 {
2354         struct reserved_combo {
2355                 char *literal;
2356                 int code;
2357                 long flag;
2358         };
2359         /* Mostly a list of accepted follow-up reserved words.
2360          * FLAG_END means we are done with the sequence, and are ready
2361          * to turn the compound list into a command.
2362          * FLAG_START means the word must start a new compound list.
2363          */
2364         static struct reserved_combo reserved_list[] = {
2365                 { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2366                 { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2367                 { "elif",  RES_ELIF,  FLAG_THEN },
2368                 { "else",  RES_ELSE,  FLAG_FI   },
2369                 { "fi",    RES_FI,    FLAG_END  },
2370                 { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2371                 { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2372                 { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2373                 { "in",    RES_IN,    FLAG_DO   },
2374                 { "do",    RES_DO,    FLAG_DONE },
2375                 { "done",  RES_DONE,  FLAG_END  }
2376         };
2377         struct reserved_combo *r;
2378         for (r=reserved_list;
2379 #define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
2380                 r<reserved_list+NRES; r++) {
2381                 if (strcmp(dest->data, r->literal) == 0) {
2382                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2383                         if (r->flag & FLAG_START) {
2384                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2385                                 debug_printf("push stack\n");
2386                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2387                                         syntax();
2388                                         free(new);
2389                                         ctx->w = RES_SNTX;
2390                                         b_reset(dest);
2391                                         return 1;
2392                                 }
2393                                 *new = *ctx;   /* physical copy */
2394                                 initialize_context(ctx);
2395                                 ctx->stack=new;
2396                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2397                                 syntax();
2398                                 ctx->w = RES_SNTX;
2399                                 b_reset(dest);
2400                                 return 1;
2401                         }
2402                         ctx->w=r->code;
2403                         ctx->old_flag = r->flag;
2404                         if (ctx->old_flag & FLAG_END) {
2405                                 struct p_context *old;
2406                                 debug_printf("pop stack\n");
2407                                 done_pipe(ctx,PIPE_SEQ);
2408                                 old = ctx->stack;
2409                                 old->child->group = ctx->list_head;
2410 #ifndef __U_BOOT__
2411                                 old->child->subshell = 0;
2412 #endif
2413                                 *ctx = *old;   /* physical copy */
2414                                 free(old);
2415                         }
2416                         b_reset (dest);
2417                         return 1;
2418                 }
2419         }
2420         return 0;
2421 }
2422
2423 /* normal return is 0.
2424  * Syntax or xglob errors return 1. */
2425 static int done_word(o_string *dest, struct p_context *ctx)
2426 {
2427         struct child_prog *child=ctx->child;
2428 #ifndef __U_BOOT__
2429         glob_t *glob_target;
2430         int gr, flags = 0;
2431 #else
2432         char *str, *s;
2433         int argc, cnt;
2434 #endif
2435
2436         debug_printf("done_word: %s %p\n", dest->data, child);
2437         if (dest->length == 0 && !dest->nonnull) {
2438                 debug_printf("  true null, ignored\n");
2439                 return 0;
2440         }
2441 #ifndef __U_BOOT__
2442         if (ctx->pending_redirect) {
2443                 glob_target = &ctx->pending_redirect->word;
2444         } else {
2445 #endif
2446                 if (child->group) {
2447                         syntax();
2448                         return 1;  /* syntax error, groups and arglists don't mix */
2449                 }
2450                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2451                         debug_printf("checking %s for reserved-ness\n",dest->data);
2452                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2453                 }
2454 #ifndef __U_BOOT__
2455                 glob_target = &child->glob_result;
2456                 if (child->argv) flags |= GLOB_APPEND;
2457 #else
2458                 for (cnt = 1, s = dest->data; s && *s; s++) {
2459                         if (*s == '\\') s++;
2460                         cnt++;
2461                 }
2462                 str = malloc(cnt);
2463                 if (!str) return 1;
2464                 if ( child->argv == NULL) {
2465                         child->argc=0;
2466                 }
2467                 argc = ++child->argc;
2468                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2469                 if (child->argv == NULL) return 1;
2470                 child->argv[argc-1]=str;
2471                 child->argv[argc]=NULL;
2472                 for (s = dest->data; s && *s; s++,str++) {
2473                         if (*s == '\\') s++;
2474                         *str = *s;
2475                 }
2476                 *str = '\0';
2477 #endif
2478 #ifndef __U_BOOT__
2479         }
2480         gr = xglob(dest, flags, glob_target);
2481         if (gr != 0) return 1;
2482 #endif
2483
2484         b_reset(dest);
2485 #ifndef __U_BOOT__
2486         if (ctx->pending_redirect) {
2487                 ctx->pending_redirect=NULL;
2488                 if (glob_target->gl_pathc != 1) {
2489                         error_msg("ambiguous redirect");
2490                         return 1;
2491                 }
2492         } else {
2493                 child->argv = glob_target->gl_pathv;
2494         }
2495 #endif
2496         if (ctx->w == RES_FOR) {
2497                 done_word(dest,ctx);
2498                 done_pipe(ctx,PIPE_SEQ);
2499         }
2500         return 0;
2501 }
2502
2503 /* The only possible error here is out of memory, in which case
2504  * xmalloc exits. */
2505 static int done_command(struct p_context *ctx)
2506 {
2507         /* The child is really already in the pipe structure, so
2508          * advance the pipe counter and make a new, null child.
2509          * Only real trickiness here is that the uncommitted
2510          * child structure, to which ctx->child points, is not
2511          * counted in pi->num_progs. */
2512         struct pipe *pi=ctx->pipe;
2513         struct child_prog *prog=ctx->child;
2514
2515         if (prog && prog->group == NULL
2516                  && prog->argv == NULL
2517 #ifndef __U_BOOT__
2518                  && prog->redirects == NULL) {
2519 #else
2520                                                                                 ) {
2521 #endif
2522                 debug_printf("done_command: skipping null command\n");
2523                 return 0;
2524         } else if (prog) {
2525                 pi->num_progs++;
2526                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2527         } else {
2528                 debug_printf("done_command: initializing\n");
2529         }
2530         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2531
2532         prog = pi->progs + pi->num_progs;
2533 #ifndef __U_BOOT__
2534         prog->redirects = NULL;
2535 #endif
2536         prog->argv = NULL;
2537 #ifndef __U_BOOT__
2538         prog->is_stopped = 0;
2539 #endif
2540         prog->group = NULL;
2541 #ifndef __U_BOOT__
2542         prog->glob_result.gl_pathv = NULL;
2543         prog->family = pi;
2544 #endif
2545         prog->sp = 0;
2546         ctx->child = prog;
2547         prog->type = ctx->type;
2548
2549         /* but ctx->pipe and ctx->list_head remain unchanged */
2550         return 0;
2551 }
2552
2553 static int done_pipe(struct p_context *ctx, pipe_style type)
2554 {
2555         struct pipe *new_p;
2556         done_command(ctx);  /* implicit closure of previous command */
2557         debug_printf("done_pipe, type %d\n", type);
2558         ctx->pipe->followup = type;
2559         ctx->pipe->r_mode = ctx->w;
2560         new_p=new_pipe();
2561         ctx->pipe->next = new_p;
2562         ctx->pipe = new_p;
2563         ctx->child = NULL;
2564         done_command(ctx);  /* set up new pipe to accept commands */
2565         return 0;
2566 }
2567
2568 #ifndef __U_BOOT__
2569 /* peek ahead in the in_str to find out if we have a "&n" construct,
2570  * as in "2>&1", that represents duplicating a file descriptor.
2571  * returns either -2 (syntax error), -1 (no &), or the number found.
2572  */
2573 static int redirect_dup_num(struct in_str *input)
2574 {
2575         int ch, d=0, ok=0;
2576         ch = b_peek(input);
2577         if (ch != '&') return -1;
2578
2579         b_getch(input);  /* get the & */
2580         ch=b_peek(input);
2581         if (ch == '-') {
2582                 b_getch(input);
2583                 return -3;  /* "-" represents "close me" */
2584         }
2585         while (isdigit(ch)) {
2586                 d = d*10+(ch-'0');
2587                 ok=1;
2588                 b_getch(input);
2589                 ch = b_peek(input);
2590         }
2591         if (ok) return d;
2592
2593         error_msg("ambiguous redirect");
2594         return -2;
2595 }
2596
2597 /* If a redirect is immediately preceded by a number, that number is
2598  * supposed to tell which file descriptor to redirect.  This routine
2599  * looks for such preceding numbers.  In an ideal world this routine
2600  * needs to handle all the following classes of redirects...
2601  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2602  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2603  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2604  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2605  * A -1 output from this program means no valid number was found, so the
2606  * caller should use the appropriate default for this redirection.
2607  */
2608 static int redirect_opt_num(o_string *o)
2609 {
2610         int num;
2611
2612         if (o->length==0) return -1;
2613         for(num=0; num<o->length; num++) {
2614                 if (!isdigit(*(o->data+num))) {
2615                         return -1;
2616                 }
2617         }
2618         /* reuse num (and save an int) */
2619         num=atoi(o->data);
2620         b_reset(o);
2621         return num;
2622 }
2623
2624 FILE *generate_stream_from_list(struct pipe *head)
2625 {
2626         FILE *pf;
2627 #if 1
2628         int pid, channel[2];
2629         if (pipe(channel)<0) perror_msg_and_die("pipe");
2630         pid=fork();
2631         if (pid<0) {
2632                 perror_msg_and_die("fork");
2633         } else if (pid==0) {
2634                 close(channel[0]);
2635                 if (channel[1] != 1) {
2636                         dup2(channel[1],1);
2637                         close(channel[1]);
2638                 }
2639 #if 0
2640 #define SURROGATE "surrogate response"
2641                 write(1,SURROGATE,sizeof(SURROGATE));
2642                 _exit(run_list(head));
2643 #else
2644                 _exit(run_list_real(head));   /* leaks memory */
2645 #endif
2646         }
2647         debug_printf("forked child %d\n",pid);
2648         close(channel[1]);
2649         pf = fdopen(channel[0],"r");
2650         debug_printf("pipe on FILE *%p\n",pf);
2651 #else
2652         free_pipe_list(head,0);
2653         pf=popen("echo surrogate response","r");
2654         debug_printf("started fake pipe on FILE *%p\n",pf);
2655 #endif
2656         return pf;
2657 }
2658
2659 /* this version hacked for testing purposes */
2660 /* return code is exit status of the process that is run. */
2661 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2662 {
2663         int retcode;
2664         o_string result=NULL_O_STRING;
2665         struct p_context inner;
2666         FILE *p;
2667         struct in_str pipe_str;
2668         initialize_context(&inner);
2669
2670         /* recursion to generate command */
2671         retcode = parse_stream(&result, &inner, input, subst_end);
2672         if (retcode != 0) return retcode;  /* syntax error or EOF */
2673         done_word(&result, &inner);
2674         done_pipe(&inner, PIPE_SEQ);
2675         b_free(&result);
2676
2677         p=generate_stream_from_list(inner.list_head);
2678         if (p==NULL) return 1;
2679         mark_open(fileno(p));
2680         setup_file_in_str(&pipe_str, p);
2681
2682         /* now send results of command back into original context */
2683         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2684         /* XXX In case of a syntax error, should we try to kill the child?
2685          * That would be tough to do right, so just read until EOF. */
2686         if (retcode == 1) {
2687                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2688         }
2689
2690         debug_printf("done reading from pipe, pclose()ing\n");
2691         /* This is the step that wait()s for the child.  Should be pretty
2692          * safe, since we just read an EOF from its stdout.  We could try
2693          * to better, by using wait(), and keeping track of background jobs
2694          * at the same time.  That would be a lot of work, and contrary
2695          * to the KISS philosophy of this program. */
2696         mark_closed(fileno(p));
2697         retcode=pclose(p);
2698         free_pipe_list(inner.list_head,0);
2699         debug_printf("pclosed, retcode=%d\n",retcode);
2700         /* XXX this process fails to trim a single trailing newline */
2701         return retcode;
2702 }
2703
2704 static int parse_group(o_string *dest, struct p_context *ctx,
2705         struct in_str *input, int ch)
2706 {
2707         int rcode, endch=0;
2708         struct p_context sub;
2709         struct child_prog *child = ctx->child;
2710         if (child->argv) {
2711                 syntax();
2712                 return 1;  /* syntax error, groups and arglists don't mix */
2713         }
2714         initialize_context(&sub);
2715         switch(ch) {
2716                 case '(': endch=')'; child->subshell=1; break;
2717                 case '{': endch='}'; break;
2718                 default: syntax();   /* really logic error */
2719         }
2720         rcode=parse_stream(dest,&sub,input,endch);
2721         done_word(dest,&sub); /* finish off the final word in the subcontext */
2722         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2723         child->group = sub.list_head;
2724         return rcode;
2725         /* child remains "open", available for possible redirects */
2726 }
2727 #endif
2728
2729 /* basically useful version until someone wants to get fancier,
2730  * see the bash man page under "Parameter Expansion" */
2731 static char *lookup_param(char *src)
2732 {
2733         char *p=NULL;
2734         if (src) {
2735                 p = getenv(src);
2736                 if (!p)
2737                         p = get_local_var(src);
2738         }
2739         return p;
2740 }
2741
2742 /* return code: 0 for OK, 1 for syntax error */
2743 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2744 {
2745 #ifndef __U_BOOT__
2746         int i, advance=0;
2747 #else
2748         int advance=0;
2749 #endif
2750 #ifndef __U_BOOT__
2751         char sep[]=" ";
2752 #endif
2753         int ch = input->peek(input);  /* first character after the $ */
2754         debug_printf("handle_dollar: ch=%c\n",ch);
2755         if (isalpha(ch)) {
2756                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2757                 ctx->child->sp++;
2758                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2759                         b_getch(input);
2760                         b_addchr(dest,ch);
2761                 }
2762                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2763 #ifndef __U_BOOT__
2764         } else if (isdigit(ch)) {
2765                 i = ch-'0';  /* XXX is $0 special? */
2766                 if (i<global_argc) {
2767                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2768                 }
2769                 advance = 1;
2770 #endif
2771         } else switch (ch) {
2772 #ifndef __U_BOOT__
2773                 case '$':
2774                         b_adduint(dest,getpid());
2775                         advance = 1;
2776                         break;
2777                 case '!':
2778                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2779                         advance = 1;
2780                         break;
2781 #endif
2782                 case '?':
2783                         b_adduint(dest,last_return_code);
2784                         advance = 1;
2785                         break;
2786 #ifndef __U_BOOT__
2787                 case '#':
2788                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2789                         advance = 1;
2790                         break;
2791 #endif
2792                 case '{':
2793                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2794                         ctx->child->sp++;
2795                         b_getch(input);
2796                         /* XXX maybe someone will try to escape the '}' */
2797                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2798                                 b_addchr(dest,ch);
2799                         }
2800                         if (ch != '}') {
2801                                 syntax();
2802                                 return 1;
2803                         }
2804                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2805                         break;
2806 #ifndef __U_BOOT__
2807                 case '(':
2808                         b_getch(input);
2809                         process_command_subs(dest, ctx, input, ')');
2810                         break;
2811                 case '*':
2812                         sep[0]=ifs[0];
2813                         for (i=1; i<global_argc; i++) {
2814                                 parse_string(dest, ctx, global_argv[i]);
2815                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2816                         }
2817                         break;
2818                 case '@':
2819                 case '-':
2820                 case '_':
2821                         /* still unhandled, but should be eventually */
2822                         error_msg("unhandled syntax: $%c",ch);
2823                         return 1;
2824                         break;
2825 #endif
2826                 default:
2827                         b_addqchr(dest,'$',dest->quote);
2828         }
2829         /* Eat the character if the flag was set.  If the compiler
2830          * is smart enough, we could substitute "b_getch(input);"
2831          * for all the "advance = 1;" above, and also end up with
2832          * a nice size-optimized program.  Hah!  That'll be the day.
2833          */
2834         if (advance) b_getch(input);
2835         return 0;
2836 }
2837
2838 #ifndef __U_BOOT__
2839 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2840 {
2841         struct in_str foo;
2842         setup_string_in_str(&foo, src);
2843         return parse_stream(dest, ctx, &foo, '\0');
2844 }
2845 #endif
2846
2847 /* return code is 0 for normal exit, 1 for syntax error */
2848 int parse_stream(o_string *dest, struct p_context *ctx,
2849         struct in_str *input, int end_trigger)
2850 {
2851         unsigned int ch, m;
2852 #ifndef __U_BOOT__
2853         int redir_fd;
2854         redir_type redir_style;
2855 #endif
2856         int next;
2857
2858         /* Only double-quote state is handled in the state variable dest->quote.
2859          * A single-quote triggers a bypass of the main loop until its mate is
2860          * found.  When recursing, quote state is passed in via dest->quote. */
2861
2862         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2863         while ((ch=b_getch(input))!=EOF) {
2864                 m = map[ch];
2865 #ifdef __U_BOOT__
2866                 if (input->__promptme == 0) return 1;
2867 #endif
2868                 next = (ch == '\n') ? 0 : b_peek(input);
2869                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2870                         ch,ch,m,dest->quote);
2871                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2872                         b_addqchr(dest, ch, dest->quote);
2873                 } else {
2874                         if (m==2) {  /* unquoted IFS */
2875                                 if (done_word(dest, ctx)) {
2876                                         return 1;
2877                                 }
2878                                 /* If we aren't performing a substitution, treat a newline as a
2879                                  * command separator.  */
2880                                 if (end_trigger != '\0' && ch=='\n')
2881                                         done_pipe(ctx,PIPE_SEQ);
2882                         }
2883                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2884                                 debug_printf("leaving parse_stream (triggered)\n");
2885                                 return 0;
2886                         }
2887 #if 0
2888                         if (ch=='\n') {
2889                                 /* Yahoo!  Time to run with it! */
2890                                 done_pipe(ctx,PIPE_SEQ);
2891                                 run_list(ctx->list_head);
2892                                 initialize_context(ctx);
2893                         }
2894 #endif
2895                         if (m!=2) switch (ch) {
2896                 case '#':
2897                         if (dest->length == 0 && !dest->quote) {
2898                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2899                         } else {
2900                                 b_addqchr(dest, ch, dest->quote);
2901                         }
2902                         break;
2903                 case '\\':
2904                         if (next == EOF) {
2905                                 syntax();
2906                                 return 1;
2907                         }
2908                         b_addqchr(dest, '\\', dest->quote);
2909                         b_addqchr(dest, b_getch(input), dest->quote);
2910                         break;
2911                 case '$':
2912                         if (handle_dollar(dest, ctx, input)!=0) return 1;
2913                         break;
2914                 case '\'':
2915                         dest->nonnull = 1;
2916                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2917 #ifdef __U_BOOT__
2918                                 if(input->__promptme == 0) return 1;
2919 #endif
2920                                 b_addchr(dest,ch);
2921                         }
2922                         if (ch==EOF) {
2923                                 syntax();
2924                                 return 1;
2925                         }
2926                         break;
2927                 case '"':
2928                         dest->nonnull = 1;
2929                         dest->quote = !dest->quote;
2930                         break;
2931 #ifndef __U_BOOT__
2932                 case '`':
2933                         process_command_subs(dest, ctx, input, '`');
2934                         break;
2935                 case '>':
2936                         redir_fd = redirect_opt_num(dest);
2937                         done_word(dest, ctx);
2938                         redir_style=REDIRECT_OVERWRITE;
2939                         if (next == '>') {
2940                                 redir_style=REDIRECT_APPEND;
2941                                 b_getch(input);
2942                         } else if (next == '(') {
2943                                 syntax();   /* until we support >(list) Process Substitution */
2944                                 return 1;
2945                         }
2946                         setup_redirect(ctx, redir_fd, redir_style, input);
2947                         break;
2948                 case '<':
2949                         redir_fd = redirect_opt_num(dest);
2950                         done_word(dest, ctx);
2951                         redir_style=REDIRECT_INPUT;
2952                         if (next == '<') {
2953                                 redir_style=REDIRECT_HEREIS;
2954                                 b_getch(input);
2955                         } else if (next == '>') {
2956                                 redir_style=REDIRECT_IO;
2957                                 b_getch(input);
2958                         } else if (next == '(') {
2959                                 syntax();   /* until we support <(list) Process Substitution */
2960                                 return 1;
2961                         }
2962                         setup_redirect(ctx, redir_fd, redir_style, input);
2963                         break;
2964 #endif
2965                 case ';':
2966                         done_word(dest, ctx);
2967                         done_pipe(ctx,PIPE_SEQ);
2968                         break;
2969                 case '&':
2970                         done_word(dest, ctx);
2971                         if (next=='&') {
2972                                 b_getch(input);
2973                                 done_pipe(ctx,PIPE_AND);
2974                         } else {
2975 #ifndef __U_BOOT__
2976                                 done_pipe(ctx,PIPE_BG);
2977 #else
2978                                 syntax_err();
2979                                 return 1;
2980 #endif
2981                         }
2982                         break;
2983                 case '|':
2984                         done_word(dest, ctx);
2985                         if (next=='|') {
2986                                 b_getch(input);
2987                                 done_pipe(ctx,PIPE_OR);
2988                         } else {
2989                                 /* we could pick up a file descriptor choice here
2990                                  * with redirect_opt_num(), but bash doesn't do it.
2991                                  * "echo foo 2| cat" yields "foo 2". */
2992 #ifndef __U_BOOT__
2993                                 done_command(ctx);
2994 #else
2995                                 syntax_err();
2996                                 return 1;
2997 #endif
2998                         }
2999                         break;
3000 #ifndef __U_BOOT__
3001                 case '(':
3002                 case '{':
3003                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3004                         break;
3005                 case ')':
3006                 case '}':
3007                         syntax();   /* Proper use of this character caught by end_trigger */
3008                         return 1;
3009                         break;
3010 #endif
3011                 default:
3012                         syntax();   /* this is really an internal logic error */
3013                         return 1;
3014                         }
3015                 }
3016         }
3017         /* complain if quote?  No, maybe we just finished a command substitution
3018          * that was quoted.  Example:
3019          * $ echo "`cat foo` plus more"
3020          * and we just got the EOF generated by the subshell that ran "cat foo"
3021          * The only real complaint is if we got an EOF when end_trigger != '\0',
3022          * that is, we were really supposed to get end_trigger, and never got
3023          * one before the EOF.  Can't use the standard "syntax error" return code,
3024          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3025         debug_printf("leaving parse_stream (EOF)\n");
3026         if (end_trigger != '\0') return -1;
3027         return 0;
3028 }
3029
3030 void mapset(const unsigned char *set, int code)
3031 {
3032         const unsigned char *s;
3033         for (s=set; *s; s++) map[*s] = code;
3034 }
3035
3036 void update_ifs_map(void)
3037 {
3038         /* char *ifs and char map[256] are both globals. */
3039         ifs = getenv("IFS");
3040         if (ifs == NULL) ifs=" \t\n";
3041         /* Precompute a list of 'flow through' behavior so it can be treated
3042          * quickly up front.  Computation is necessary because of IFS.
3043          * Special case handling of IFS == " \t\n" is not implemented.
3044          * The map[] array only really needs two bits each, and on most machines
3045          * that would be faster because of the reduced L1 cache footprint.
3046          */
3047         memset(map,0,sizeof(map)); /* most characters flow through always */
3048 #ifndef __U_BOOT__
3049         mapset("\\$'\"`", 3);      /* never flow through */
3050         mapset("<>;&|(){}#", 1);   /* flow through if quoted */
3051 #else
3052         mapset("\\$'\"", 3);       /* never flow through */
3053         mapset(";&|#", 1);         /* flow through if quoted */
3054 #endif
3055         mapset(ifs, 2);            /* also flow through if quoted */
3056 }
3057
3058 /* most recursion does not come through here, the exeception is
3059  * from builtin_source() */
3060 int parse_stream_outer(struct in_str *inp, int flag)
3061 {
3062
3063         struct p_context ctx;
3064         o_string temp=NULL_O_STRING;
3065         int rcode;
3066 #ifdef __U_BOOT__
3067         int code = 0;
3068 #endif
3069         do {
3070                 ctx.type = flag;
3071                 initialize_context(&ctx);
3072                 update_ifs_map();
3073                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
3074                 inp->promptmode=1;
3075                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3076 #ifdef __U_BOOT__
3077                 if (rcode == 1) flag_repeat = 0;
3078 #endif
3079                 if (rcode != 1 && ctx.old_flag != 0) {
3080                         syntax();
3081 #ifdef __U_BOOT__
3082                         flag_repeat = 0;
3083 #endif
3084                 }
3085                 if (rcode != 1 && ctx.old_flag == 0) {
3086                         done_word(&temp, &ctx);
3087                         done_pipe(&ctx,PIPE_SEQ);
3088 #ifndef __U_BOOT__
3089                         run_list(ctx.list_head);
3090 #else
3091                         if (((code = run_list(ctx.list_head)) == -1))
3092                             flag_repeat = 0;
3093 #endif
3094                 } else {
3095                         if (ctx.old_flag != 0) {
3096                                 free(ctx.stack);
3097                                 b_reset(&temp);
3098                         }
3099 #ifdef __U_BOOT__
3100                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3101                         inp->__promptme = 1;
3102 #endif
3103                         temp.nonnull = 0;
3104                         temp.quote = 0;
3105                         inp->p = NULL;
3106                         free_pipe_list(ctx.list_head,0);
3107                 }
3108                 b_free(&temp);
3109         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3110 #ifndef __U_BOOT__
3111         return 0;
3112 #else
3113         return (code != 0) ? 1 : 0;
3114 #endif /* __U_BOOT__ */
3115 }
3116
3117 #ifndef __U_BOOT__
3118 static int parse_string_outer(const char *s, int flag)
3119 #else
3120 int parse_string_outer(char *s, int flag)
3121 #endif  /* __U_BOOT__ */
3122 {
3123         struct in_str input;
3124 #ifdef __U_BOOT__
3125         char *p = NULL;
3126         int rcode;
3127         if ( !s || !*s)
3128                 return 1;
3129         if (!(p = strchr(s, '\n')) || *++p) {
3130                 p = xmalloc(strlen(s) + 2);
3131                 strcpy(p, s);
3132                 strcat(p, "\n");
3133                 setup_string_in_str(&input, p);
3134                 rcode = parse_stream_outer(&input, flag);
3135                 free(p);
3136                 return rcode;
3137         } else {
3138 #endif
3139         setup_string_in_str(&input, s);
3140         return parse_stream_outer(&input, flag);
3141 #ifdef __U_BOOT__
3142         }
3143 #endif
3144 }
3145
3146 #ifndef __U_BOOT__
3147 static int parse_file_outer(FILE *f)
3148 #else
3149 int parse_file_outer(void)
3150 #endif
3151 {
3152         int rcode;
3153         struct in_str input;
3154 #ifndef __U_BOOT__
3155         setup_file_in_str(&input, f);
3156 #else
3157         setup_file_in_str(&input);
3158 #endif
3159         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3160         return rcode;
3161 }
3162
3163 #ifdef __U_BOOT__
3164 int u_boot_hush_start(void)
3165 {
3166         top_vars = malloc(sizeof(struct variables));
3167         top_vars->name = "HUSH_VERSION";
3168         top_vars->value = "0.01";
3169         top_vars->next = 0;
3170         top_vars->flg_export = 0;
3171         top_vars->flg_read_only = 1;
3172         return 0;
3173 }
3174
3175 static void *xmalloc(size_t size)
3176 {
3177         void *p = NULL;
3178
3179         if (!(p = malloc(size))) {
3180             printf("ERROR : memory not allocated\n");
3181             for(;;);
3182         }
3183         return p;
3184 }
3185
3186 static void *xrealloc(void *ptr, size_t size)
3187 {
3188         void *p = NULL;
3189
3190         if (!(p = realloc(ptr, size))) {
3191             printf("ERROR : memory not allocated\n");
3192             for(;;);
3193         }
3194         return p;
3195 }
3196 #endif /* __U_BOOT__ */
3197
3198 #ifndef __U_BOOT__
3199 /* Make sure we have a controlling tty.  If we get started under a job
3200  * aware app (like bash for example), make sure we are now in charge so
3201  * we don't fight over who gets the foreground */
3202 static void setup_job_control()
3203 {
3204         static pid_t shell_pgrp;
3205         /* Loop until we are in the foreground.  */
3206         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3207                 kill (- shell_pgrp, SIGTTIN);
3208
3209         /* Ignore interactive and job-control signals.  */
3210         signal(SIGINT, SIG_IGN);
3211         signal(SIGQUIT, SIG_IGN);
3212         signal(SIGTERM, SIG_IGN);
3213         signal(SIGTSTP, SIG_IGN);
3214         signal(SIGTTIN, SIG_IGN);
3215         signal(SIGTTOU, SIG_IGN);
3216         signal(SIGCHLD, SIG_IGN);
3217
3218         /* Put ourselves in our own process group.  */
3219         setsid();
3220         shell_pgrp = getpid ();
3221         setpgid (shell_pgrp, shell_pgrp);
3222
3223         /* Grab control of the terminal.  */
3224         tcsetpgrp(shell_terminal, shell_pgrp);
3225 }
3226
3227 int hush_main(int argc, char **argv)
3228 {
3229         int opt;
3230         FILE *input;
3231         char **e = environ;
3232
3233         /* XXX what should these be while sourcing /etc/profile? */
3234         global_argc = argc;
3235         global_argv = argv;
3236
3237         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3238          * hush_main(), therefore we cannot rely on the BSS to zero out this
3239          * stuff.  Reset these to 0 every time. */
3240         ifs = NULL;
3241         /* map[] is taken care of with call to update_ifs_map() */
3242         fake_mode = 0;
3243         interactive = 0;
3244         close_me_head = NULL;
3245         last_bg_pid = 0;
3246         job_list = NULL;
3247         last_jobid = 0;
3248
3249         /* Initialize some more globals to non-zero values */
3250         set_cwd();
3251 #ifdef BB_FEATURE_COMMAND_EDITING
3252         cmdedit_set_initial_prompt();
3253 #else
3254         PS1 = NULL;
3255 #endif
3256         PS2 = "> ";
3257
3258         /* initialize our shell local variables with the values
3259          * currently living in the environment */
3260         if (e) {
3261                 for (; *e; e++)
3262                         set_local_var(*e, 2);   /* without call putenv() */
3263         }
3264
3265         last_return_code=EXIT_SUCCESS;
3266
3267
3268         if (argv[0] && argv[0][0] == '-') {
3269                 debug_printf("\nsourcing /etc/profile\n");
3270                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3271                         mark_open(fileno(input));
3272                         parse_file_outer(input);
3273                         mark_closed(fileno(input));
3274                         fclose(input);
3275                 }
3276         }
3277         input=stdin;
3278
3279         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3280                 switch (opt) {
3281                         case 'c':
3282                                 {
3283                                         global_argv = argv+optind;
3284                                         global_argc = argc-optind;
3285                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3286                                         goto final_return;
3287                                 }
3288                                 break;
3289                         case 'i':
3290                                 interactive++;
3291                                 break;
3292                         case 'f':
3293                                 fake_mode++;
3294                                 break;
3295                         default:
3296 #ifndef BB_VER
3297                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3298                                                 "   or: sh -c command [args]...\n\n");
3299                                 exit(EXIT_FAILURE);
3300 #else
3301                                 show_usage();
3302 #endif
3303                 }
3304         }
3305         /* A shell is interactive if the `-i' flag was given, or if all of
3306          * the following conditions are met:
3307          *        no -c command
3308          *    no arguments remaining or the -s flag given
3309          *    standard input is a terminal
3310          *    standard output is a terminal
3311          *    Refer to Posix.2, the description of the `sh' utility. */
3312         if (argv[optind]==NULL && input==stdin &&
3313                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3314                 interactive++;
3315         }
3316
3317         debug_printf("\ninteractive=%d\n", interactive);
3318         if (interactive) {
3319                 /* Looks like they want an interactive shell */
3320                 fprintf(stdout, "\nhush -- the humble shell v0.01 (testing)\n\n");
3321                 setup_job_control();
3322         }
3323
3324         if (argv[optind]==NULL) {
3325                 opt=parse_file_outer(stdin);
3326                 goto final_return;
3327         }
3328
3329         debug_printf("\nrunning script '%s'\n", argv[optind]);
3330         global_argv = argv+optind;
3331         global_argc = argc-optind;
3332         input = xfopen(argv[optind], "r");
3333         opt = parse_file_outer(input);
3334
3335 #ifdef BB_FEATURE_CLEAN_UP
3336         fclose(input);
3337         if (cwd && cwd != unknown)
3338                 free((char*)cwd);
3339         {
3340                 struct variables *cur, *tmp;
3341                 for(cur = top_vars; cur; cur = tmp) {
3342                         tmp = cur->next;
3343                         if (!cur->flg_read_only) {
3344                                 free(cur->name);
3345                                 free(cur->value);
3346                                 free(cur);
3347                         }
3348                 }
3349         }
3350 #endif
3351
3352 final_return:
3353         return(opt?opt:last_return_code);
3354 }
3355 #endif
3356
3357 static char *insert_var_value(char *inp)
3358 {
3359         int res_str_len = 0;
3360         int len;
3361         int done = 0;
3362         char *p, *p1, *res_str = NULL;
3363
3364         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3365                 if (p != inp) {
3366                         len = p - inp;
3367                         res_str = xrealloc(res_str, (res_str_len + len));
3368                         strncpy((res_str + res_str_len), inp, len);
3369                         res_str_len += len;
3370                 }
3371                 inp = ++p;
3372                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3373                 *p = '\0';
3374                 if ((p1 = lookup_param(inp))) {
3375                         len = res_str_len + strlen(p1);
3376                         res_str = xrealloc(res_str, (1 + len));
3377                         strcpy((res_str + res_str_len), p1);
3378                         res_str_len = len;
3379                 }
3380                 *p = SPECIAL_VAR_SYMBOL;
3381                 inp = ++p;
3382                 done = 1;
3383         }
3384         if (done) {
3385                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3386                 strcpy((res_str + res_str_len), inp);
3387                 while ((p = strchr(res_str, '\n'))) {
3388                         *p = ' ';
3389                 }
3390         }
3391         return (res_str == NULL) ? inp : res_str;
3392 }
3393
3394 static char **make_list_in(char **inp, char *name)
3395 {
3396         int len, i;
3397         int name_len = strlen(name);
3398         int n = 0;
3399         char **list;
3400         char *p1, *p2, *p3;
3401
3402         /* create list of variable values */
3403         list = xmalloc(sizeof(*list));
3404         for (i = 0; inp[i]; i++) {
3405                 p3 = insert_var_value(inp[i]);
3406                 p1 = p3;
3407                 while (*p1) {
3408                         if ((*p1 == ' ')) {
3409                                 p1++;
3410                                 continue;
3411                         }
3412                         if ((p2 = strchr(p1, ' '))) {
3413                                 len = p2 - p1;
3414                         } else {
3415                                 len = strlen(p1);
3416                                 p2 = p1 + len;
3417                         }
3418                         /* we use n + 2 in realloc for list,because we add
3419                          * new element and then we will add NULL element */
3420                         list = xrealloc(list, sizeof(*list) * (n + 2));
3421                         list[n] = xmalloc(2 + name_len + len);
3422                         strcpy(list[n], name);
3423                         strcat(list[n], "=");
3424                         strncat(list[n], p1, len);
3425                         list[n++][name_len + len + 1] = '\0';
3426                         p1 = p2;
3427                 }
3428                 if (p3 != inp[i]) free(p3);
3429         }
3430         list[n] = NULL;
3431         return list;
3432 }
3433
3434 /* Make new string for parser */
3435 static char * make_string(char ** inp)
3436 {
3437         char *p;
3438         char *str = NULL;
3439         int n;
3440         int len = 2;
3441
3442         for (n = 0; inp[n]; n++) {
3443                 p = insert_var_value(inp[n]);
3444                 str = xrealloc(str, (len + strlen(p)));
3445                 if (n) {
3446                         strcat(str, " ");
3447                 } else {
3448                         *str = '\0';
3449                 }
3450                 strcat(str, p);
3451                 len = strlen(str) + 3;
3452                 if (p != inp[n]) free(p);
3453         }
3454         len = strlen(str);
3455         *(str + len) = '\n';
3456         *(str + len + 1) = '\0';
3457         return str;
3458 }
3459
3460 #endif /* CFG_HUSH_PARSER */
3461 /****************************************************************************/